Today's Message Index:
----------------------
1. 06:41 AM - Re: Re: dim able strip LED lighting (Richard Girard)
2. 07:55 AM - Re: Re: dim able strip LED lighting (John McMahon)
3. 07:55 AM - Re: dim able strip LED lighting / off topic (glen matejcek)
4. 07:55 AM - Re: Re: dim able strip LED lighting (Jim Wickert)
5. 07:57 AM - Re: Re: dim able strip LED lighting (Lynn Riggs)
6. 08:12 AM - Thermally robust PM rectifier/regulators (Robert L. Nuckolls, III)
7. 09:06 AM - Re: Re: dim able strip LED lighting (John Cox)
8. 09:14 AM - Re: Re: dim able strip LED lighting (Lynn Riggs)
9. 10:09 AM - Re: Re: dim able strip LED lighting ()
10. 10:48 AM - Re: Thermally robust PM rectifier/regulators (Richard Girard)
11. 11:09 AM - Re: Thermally robust PM rectifier/regulators (Robert L. Nuckolls, III)
12. 11:58 AM - Re: Thermally robust PM rectifier/regulators (Richard Girard)
13. 05:01 PM - Re: Re: dim able strip LED lighting (rayj)
14. 08:07 PM - Re: Re: dim able strip LED lighting (Jim Wickert)
Message 1
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| Subject: | Re: dim able strip LED lighting |
Using the example of Boeing and Airbus for cockpit lighting in a good
example of not examining the application before making a decision, IMHO.
When was the last time an airline crew really needed to have good night
vision for looking outside the cockpit? Unless you plan on flying on
instruments from takeoff to touchdown, or very nearly, is this the wise
choice?
Even using the military, particularly what the helicopter cockpits use, is
questionable since their decision may have been driven as much by
compatibility with night vision equipment as the human eye.
Just exactly how much improvement is blue/green over red? Does the
difference amount to anything more that picking the fly poop from the
pepper, or are we dealing with an unquantifiable "coolness factor"?
Rick Girard
On Mon, Sep 6, 2010 at 10:04 PM, RV7ASask <rv7alamb@sasktel.net> wrote:
>
>
> >>This is an interesting dimmer. =EF=BDDoes it have the noise problems
that Bob
> was writing about?
>
> I am just finishing installing the radios so I can't tell you about noise
> problems at this time. More to follow.
>
> Weighing in on the color of the light. I said earlier 'Stick with White.'
I
> think both Mr Boeing and Mr Airbus have opted for white in the cockpit an
d I
> think they got it right.
>
> David
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=311626#311626
>
>
===========
===========
===========
===========
>
>
--
Zulu Delta
Kolb Mk IIIC
582 Gray head
4.00 C gearbox
3 blade WD
Thanks, Homer GBYM
It is not bigotry to be certain we are right; but it is bigotry to be unabl
e
to imagine how we might possibly have gone wrong.
- G.K. Chesterton
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| Subject: | Re: dim able strip LED lighting |
And remember when the red cockpit lighting made all of the fan markers and
LF ranges mysteriously disappear from our charts on night flights!
On Mon, Sep 6, 2010 at 7:25 PM, Lynn Riggs <riggs_la@yahoo.com> wrote:
>
> I have flown with both, I am a retired Army pilot, and can tell you that
> the
> blue-green lighting has less of an impact on night vision than red and is
> easier to read charts with. At lease the blue-green the Army used.
>
> Lynn
>
> -----Original Message-----
> From: owner-aeroelectric-list-server@matronics.com
> [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Gerry
> van
> Dyk
> Sent: Monday, September 06, 2010 6:43 PM
> To: aeroelectric-list@matronics.com
> Subject: RE: AeroElectric-List: Re: dim able strip LED lighting
>
> <gerry.vandyk@shaw.ca>
>
> That is rather curious. Amateur astronomers use red flashlights at night
> when looking at their charts, the reason being red light doesn't cause the
> eye's iris to close, which kills dark adapted vision. When observing
> objects through larger telescopes one can occasionally pick up a blue-green
> color in subjects like the Ring Nebula (M57)the reason being the color
> receptors in the retina pick up the middle of the visible spectrum (520
> nanometer wavelength)at the lowest light levels. I have a suspicion that
> this study determined that blue-green is the easiest to see, which is
> different than the best color for preserving night vision.
>
> http://www.oneminuteastronomer.com/astro-course-day-5/
>
> I would suggest doing some research into WWII night fighters. For one, the
> P-61 Black Widow used red cockpit lighting. Red allows you to look at the
> instruments, then look out the window without having to wait for your eyes
> to re-adapt to the darkness.
>
> Gerry
>
> -----Original Message-----
> From: owner-aeroelectric-list-server@matronics.com
> [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Lynn
> Riggs
> Sent: September 6, 2010 2:24 PM
> To: aeroelectric-list@matronics.com
> Subject: RE: AeroElectric-List: Re: dim able strip LED lighting
>
>
>
> White is not good for your night vision. The military has found that a
> blue-green light is the best in night operations.
>
> Lynn
>
>
--
John McMahon
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| Subject: | RE: dim able strip LED lighting / off topic |
Just a data point on lighting and combat- I've been told that the biggest
advantage of red lighting in at least one application is that a useable
level of red light can't be seen from nearly as far away as white light
can, thereby making it harder for the other guy to see you. I have no
personal knowledge to back that up, however.
Glen Matejcek
aerobubba@earthlink.ne
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| Subject: | Re: dim able strip LED lighting |
Jim Wickert here, I have been following this thread and have the
following to put up for added fodder. We have a Government Marine
contract which we are working on that has a section for Night
Illumination of Instrumentation and we are doing the scope research now.
Below is some interesting information and food for thought. At this
time our general consensus is Soft White Flood of panels? We have not
released our findings to our customer however. Take care sorry for the
amount of text but this is only a snip of the 13 page findings.
FLITELite Light Color, Intensity & Night Vision:
Pilots have a choice of FLITELite colors - NVIS White (more information
on NVIS White <http://www.flitelite.com/isite/nvis.htm> ), Soft White
that is NVIS friendly, Green, Red and Blue. The best light choice is
NVIS White, followed by soft white, for a light that will protect your
central night vision and provide full spectrum light. Green and Blue
will protect central night vision as well, but blues and greens will
disappear with this color of light - something for a pilot to consider
prior to use. Red is also available, which will protect peripheral night
vision, but not central vision as well as the soft white, blue and
green. Red's on charts will also not be visible with red light, another
consideration for the pilot to consider when making a color choice.
The eyes are comprised of Rods and Cones. We hear people talk about Rods
being for night vision, and Cones for day vision, and while they both
have their special attributes, it would be better to classify them in
the aviation environment at Peripheral (Rods) and Central (Cones)
vision. Both rods and cones have a day and night mode, and they both
react to light at different rates, and to have sensitivity to different
light frequencies.
Rods surround the periphery of the eye and are used for peripheral
vision, and night vision. They do not see color, and do not detect
motion. Rods only provide non-color vision at an acuity of 20/200. Rods
are most susceptible to blue light. You never read, or scan your
instruments with your Rods - or your peripheral vision - think about it.
You are reading this article with your central vision - your cones.
Cones are used for color, central vision, with visual acuity of 20/20.
The cones have a focal width of approximately 20 to 30 degrees. Cones
are most susceptible to red light.
Cones are used when you read, day or night. During the day we read with
our cones - during the night we need a light to read - obvious, but it
shatters the red light myth in the aviation cockpit.
http://www.flitelite.com/isite/images/rcdist.gif
So the question is what is the best light that will provide your eyes,
and brain with the best light for reading? The answer is a dim white
light. Look inside any of the new jets, and you will find that the
lighting is white. Military cockpits specify NVIS White
<http://www.flitelite.com/isite/nvis.htm> . NVIS White appears to have a
green tint, but it is a full spectrum light. More on NVIS Compatibility
<http://www.flitelite.com/isite/nvis.htm>
FLITELite is set to a 25 degree field of view to maximize the physiology
of the pilot=99s eye. But to preserve night vision the intensity
of the light is what matters. By using a full spectrum white light, the
full spectrum light and low reflection reduces the amount of light
needed. The 25 degree field is critical to keep the light out of our
peripheral vision so we can look for traffic, and gauge height when we
are making that perfect night landing.
Under red light, magenta symbols disappear on charts, and during
electrical failures, red markings on instruments and gauges are
unreadable. Blue light will make Blue 100LL fuel disappear.
Unaided night vision even now in the 21st century is still the subject
of some controversy.
For those just looking for an executive answer as to what supplemental
lighting should be used to reduced the recovery time back to night
vision (dark adapted or scotopic) here it is: a fully dimmable white
light! This of course is a very incomplete answer but so are the answers
red or blue-green and you should know why.
Let=99s start with red, specifically what I will call the red
light myth.
I believe the myth started in the photographic darkroom.
Until about 1906 most photosensitive material (plate, film, and paper)
was not very sensitive to red. Some of these orthochromatic materials
are still used. This allowed these materials to be dealt with for a
short time under a relative bright red light because the human eye can
see red if the level is bright enough. The fact that L.E.D.s (having a
number of advantages over other light sources) were economically only
available in red for some time has also help to perpetuate this myth.
As more research about the eye was done it was found that the structure
responsible for very low light vision, the rods, were also not very
sensitive to red.
It was assumed then that like film you could use red light, which is
seen by the red sensitive cones (there are also blue and green sensitive
cones to give color vision), without affecting the rods.
It takes a while for true night vision to be recovered. About 10
minutes for 10%, 30-45 minutes for 80%, the rest may take hours, days,
or a week. The issue is the chemical in the eye, rhodopsin - commonly
called visual purple, is broken down quickly by light. The main issue
then is intensity; color is only an issue because the rods (responsible
for night vision) are most sensitive at a particular color. That color
is a blue-green (507nm) similar to traffic light green (which is this
color for a entirely different reason). It would seem that using the
lowest brightness (using this color) additional light needed for a task
is the best bet to retain this dark adaptation because it allows rods to
function at their best.
Unfortunately there are a number of drawbacks using only night vision.
Among these are:
* The inability to distinguish colors.
* No detail can be seen (about the same as 20/200 vision in daylight).
* That nothing can be seen directly in front of the eyes (no rods in the
center of the retina), you must learn to look about 15-20=C2=B0 off
center.
* Only motion can be detected well, therefore you may have to learn to
move your eyes to detect something that doesn't move.
* Objects that aren't moving appear to move (autokinesis). This has
probably led to a number of plane crashes.
If you need to see directly in front of you or see detail you need red.
Like many myths the red light myth has some basis in fact. The red
truth?
Why red? The center 1.5% of your retina (the fovea) which provides you
with most detailed vision is packed almost exclusively with red
sensitive cones.
This is the same area that has no rods and is responsible for the night
blind spot. There are fewer total green sensitive cones than red. The
number of blue sensitive cones is very small compared to green and red.
Which is just as well since the lens in the human eye cannot focus red
and blue at the same time. And using green really only changes
perceived brightness because of the way the signals are processed in our
neural pathways. Unlike a digital camera, more pixels, in this case,
doesn't give us more detail.
rod density vs. conesChart showing the distribution of rods vs cones.
Note the absence of rods in the center and the absence of both about
15=C2=B0 away from the the center toward the nose where the optic nerve
passes.
At first glance the tendency would be to pick the hue of red at which we
are most sensitive (566nm) which would make sense except for the real
reason: we don't want to involve the rods. The reason is the rods share
the neural pathways with the cones so that you have this fuzzy image
overriding the detailed one. This effect disappears at slightly higher
mesopic levels which is why white is a good choice for most tasks. Many
people look at the numbers for sensitivity for rods and cones and forget
that in most cases the numbers have been adjusted so that rod peek
sensitive matches cone peak. Rods are in fact sensitive well into the
infrared (not too useful except to know that light you can barely sense
can adversely impact your night vision). The key then is finding a hue
that we can have at a high enough intensity that we can see the detail
we need without activating our rods to the point where they obscure that
detail. Most source say this should be nothing shorter than 650nm.
Experimentation shows a L.E.D. with a peek around 700nm seems to work
best (perceived as a deep red). Note that red may be fatiguing to the
eyes.
Conclusions:
* No matter what your color choice it must be fully adjustable for
intensity.
* If you need the fastest dark adaptation recovery and can adjust to the
limitations, or everyone in your group is using night vision equipment
then blue-green.
* If you must see detail (reading a star chart, or instrument settings)
and can lose peripheral vision (see note 1)
<http://stlplaces.com/night_vision_red_myth/#note1> , then a very long
wavelength red at a very low level. Red really only has an advantage at
very low levels (were the night blind spot is very obvious).
* A general walking around light so that you don't trip over the tripod,
knock over equipment or bump into people, then blue-green with enough
red added to get rid of the night blind spot, or maybe just use white.
Blue-green at higher brightness also works very well and at a lower
intensity than white.
* If you need to see color and detail then likely the best choice is the
dimmest white light for the shortest amount of time.
* If you are in the military you must follow their rules; hopefully they
will have a good course in unassisted night vision.
* If you are a pilot and say you only fly in the day, you should be
aware of the problems of night vision and should consider a basic
(ground) course in night flying.
* If you wonder why no one else has drawn these conclusions look at the
dashboard of most cars. The markings are large, the pointers are large
and an orange-red (a compromise, for certain "color blind" persons) and
at night it is edge lit with blue-green filtered fully intensity
adjustable light.
For Best night vision:
* Be sure you are getting enough vitamin A or its precursor
beta-carotene in your diet (needed for the visual purple).
* Green leafy stuff is best followed by vegetables that have an orange
color. Yes that includes carrots but spinach or dark leaf lettuce are
better. It is possible to get too much vitamin A especially as a
supplement.
* Keep up your general health. Smoking is also very bad for night
vision, as are most illegal drugs and some prescription drugs.
* Keep you blood sugar level as even as possible. No meal skipping.
Six small meals are better than three large meals. For carbohydrates
favor starches (potatoes, rice, and bread) over simple sugars (sweets,
alcohol).
* Use dark neutral gray sunglasses, that pass no more that 15% in full
sun, when outside during the day.
True night blindness is rare. Most of what people call night blindness
is either a lack of vitamin A in the diet or a failure to understand the
night blind spot.
Cataracts, even minor ones, increase the effects of glare at night and
the eye's lens does yellow and passes less light as we age which may
contribute to what some call night blindness.
Note: The red filtered light at the intensity most people use is likely
decreasing night vision much more than a properly dimmed white or
blue-green light would!
Note: There are day blind spots also but are in a different position in
each eye so are less of a problem.
Note: Blue-green (also called cyan, turquoise, teal and other names) as
used here is NOT the combination of two colors but is a single
particular hue. I use the most common name for that hue.
Mil-STD 1472F 5.8.2.2 (table XVI) display lighting
Brightness of markings
Condition of use
Lighting Technique *
cd/m2
foot-lamberts
Brightness Adjustment
Indicator reading, dark adaptation necessary
Red flood, indirect, or both, with operator choice
0.07-0.35
(0.02-0.1)
Continuous throughout range
Indicator reading, dark adaptation not necessary but desirable
Red or low-color-temperature white flood, indirect, or both, with
operator choice
0.07-3.5-
(0.02-1.0)
Continuous throughout range
Indicator reading, dark adaptation not necessary
White flood
3.5-70
(1-20)
Fixed or continuous
Panel monitoring, dark adaptation necessary
Red edge lighting, red or white flood, or both, with operator choice
0.07-3.5
(0.02-1.0)
Continuous throughout range
Panel monitoring, dark adaptation not necessary
White flood
35-70
(10-20)
Fixed or continuous
Possible exposure to bright flashes, restricted daylight
White flood
35-70
(10-20)
Fixed
Chart reading, dark adaptation necessary
Red or white flood with operator choice
0.35-3.50
(0.1-1.0)
Continuous throughout range
Chart reading, dark adaptation not necessary
White flood
17-70
(5-20)
Fixed or continuous
* Where detection of ground vehicles or other protected assets by image
intensifier night vision devices must be minimized, blue-green light
(incandescent filament through a filter which passes only wave lengths
shorter than 600 nm) should be used in lieu of red light.
- Possible error in original, read as: 0.07-0.35, likely
occurred when converted to metric.
_____
This is intended only as an overview; no warranty of this information is
expressed or implied
_____
[Update 17 Nov 2003] I find new myths are springing up. Such as
blue-green L.E.D.s are emitting two colors of light. This is a
mis-understanding of the color name and that this is the most accepted
name for this one color. Another is that blue improves night vision.
While at somewhat higher levels it, of course, is stimulating the rods.
It is not an optimum color. Another long standing myth is that human
visual perception is based on three colors when it is really based on
four. The rods are usually ignored because many people believe,
wrongly, that at the brightness at which we perceive color the rods are
no longer providing our brains with any information. In fact the
perception of brightness is highly influenced by the rods well into the
photopic (bright light) range of vision. Fluorescent lamp manufacturers
have used this knowledge for a long time. "Cool White" lamps have an
additional amount of green phosphor added to make us "see" them as being
brighter! Of course the whole subject of color vision and the variances
thereof (wrongly called "color blindness") will require a number of new
pages even in synopsis form.
A point I forgot to cover is that to help preserve night vision in one
eye the other may be closed or covered if you know you are about to be
exposed to a brighter light, such as from a oncoming vehicle. For
normal observation both eyes should be kept open. If it is difficult to
concentrate on the desired image the eye not being used may be covered
but not closed. Closing affects focus and possibly acuity.
[Update 14 Dec 2003] A very important point barely mentioned in the
original is that human peripheral vision is almost completely rod based!
The implication then is that we cannot see color at the edges of our
vision. If you think we can, try this simple experiment. You will need
a small assortment of color cards (try sheets of construction paper) and
someone to assist you. Sit looking straight ahead while you=99re
assistant, about 6 to 10 feet away, slowly moves a random color card
into the margin of your vision. Now, while still looking straight
ahead, what color is the card?
This is the second most important factor that has been ignored in the
design of outdoor lighting, the first being glare! However this study
<http://stlplaces.com/cgi/redirect.cgi?http://dmses.dot.gov/docimages/pdf
66/133155_web.pdf> (in pdf), at the U. S. Dept. of Transportation, is a
subjective study of blue tinted headlamps.
[Update 23 Jan 2004] A few random notes to be better integrated into
this document later.
Luminances are approximate and will vary with the individual and
conditions.
Vision luminance rage 1 * 10-6 to 1 * 106 cd/M2
Rods luminance rage 1 * 10-6 to 1 * 103 cd/M2 (may still play a roll
above this range)
Cones luminance rage 1 * 10-3 to 1 * 106 cd/M2
Explain "Purinke shift"
20/20 vision is the ability to resolve 1 minute of arc at 20 feet.
Discuss Ricco's Law.
Discuss afterimages.
LITELite NVIS Compatibility
MIL-STD-3009 was developed by the Department of Defense in February 2001
and superceded MIL-L-85762A. It specifies that NVIS White for crew
cockpit and utility lighting. NVIS Green A is grand fathered into the
cockpit for certain applications, but not for new applications.
The chromacity of NVIS White makes it a full spectrum light even though
is appears to have a green tint. Visible light can be split into the
three primary colors, red, green and blue. The eye needs two primary
colors to see 'white'. NVIS White, in simple terms is blue range through
the green range. NVIS goggles filters allow a thin band of green light
though the lens - so that users can see heads up displays and other
required applications through the goggles.
The level of light with respect to the chromacity is important due to
this leak (filter) in the goggles. Other manufacturers claim to be the
'only authorized' lights produced since they meet a request for proposal
standard. These claims are false - they have never tested FLITELite
products how could they know? FLITELite meets and exceeds non-binding
RFP standards, AND meets the modern, more stringent MIL-STD-3009, which
is a binding requirement specified by the military.
General Aviation pilots can benefit from this technology. This light
spectrum and intensity is perfect for general night vision use as well.
Read MIL-STD-3009
<http://www.flitelite.com/isite/support/MIL_STD_3009.pdf> here.
http://www.flitelite.com/isite/images/nvischart.jpg
http://www.flitelite.com/isite/images/range.jpg
FLITELite minimizes the crossover zone by using a special combination of
LED's and Filter material. The filter material ensures that the light
greater than 600 nm is not transmitted.
http://www.flitelite.com/isite/images/nvissys.jpg
Jim Wickert
Vision #159 =9CVision some will have some will not=9D
Tel 920-467-0219
Cell 920-912-1014
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
Richard Girard
Sent: Tuesday, September 07, 2010 8:35 AM
Subject: Re: AeroElectric-List: Re: dim able strip LED lighting
Using the example of Boeing and Airbus for cockpit lighting in a good
example of not examining the application before making a decision, IMHO.
When was the last time an airline crew really needed to have good night
vision for looking outside the cockpit? Unless you plan on flying on
instruments from takeoff to touchdown, or very nearly, is this the wise
choice?
Even using the military, particularly what the helicopter cockpits use,
is questionable since their decision may have been driven as much by
compatibility with night vision equipment as the human eye.
Just exactly how much improvement is blue/green over red? Does the
difference amount to anything more that picking the fly poop from the
pepper, or are we dealing with an unquantifiable "coolness factor"?
Rick Girard
On Mon, Sep 6, 2010 at 10:04 PM, RV7ASask <rv7alamb@sasktel.net> wrote:
<rv7alamb@sasktel.net>
>>This is an interesting dimmer. =EF=BDDoes it have the noise
problems that Bob was writing about?
I am just finishing installing the radios so I can't tell you about
noise problems at this time. More to follow.
Weighing in on the color of the light. I said earlier 'Stick with
White.' I think both Mr Boeing and Mr Airbus have opted for white in the
cockpit and I think they got it right.
David
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=311626#311626
-
ric-List"
target="_blank">http://www.matronics.com/Navigator?AeroElectric-List
MS -
k">http://forums.matronics.com
e -
-Matt Dralle, List Admin.
t="_blank">http://www.matronics.com/contribution
--
Zulu Delta
Kolb Mk IIIC
582 Gray head
4.00 C gearbox
3 blade WD
Thanks, Homer GBYM
It is not bigotry to be certain we are right; but it is bigotry to be
unable to imagine how we might possibly have gone wrong.
- G.K. Chesterton
Message 5
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| Subject: | Re: dim able strip LED lighting |
Your point with the white light in the Airbus is quite valid. As to the
NVG compatibility, when flying with NVG=99s the cockpit lighting
is turndown so low you cannot read your instrument without using the
NVG=99s and color does not make much difference. The Army was
looking for a different lighting in the cockpit because the red lighting
gave off an IR signature which is not good. They found that the
blue-green light was preferred buy their pilots, especially the older
pilots, and did not give off an IR signature. I have over 600 hours of
flight time at night and a lot of that flying low level or terrain
flight in VFR conditions with about 60 hours using the blue-green
lighting which I thought to be much better than the red lighting. I
would not use white lighting in the cockpit for night VFR flight. The
problem I have found is the blue-green cockpit lighting is not
available.
Lynn
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
Richard Girard
Sent: Tuesday, September 07, 2010 8:35 AM
Subject: Re: AeroElectric-List: Re: dim able strip LED lighting
Using the example of Boeing and Airbus for cockpit lighting in a good
example of not examining the application before making a decision, IMHO.
When was the last time an airline crew really needed to have good night
vision for looking outside the cockpit? Unless you plan on flying on
instruments from takeoff to touchdown, or very nearly, is this the wise
choice?
Even using the military, particularly what the helicopter cockpits use,
is questionable since their decision may have been driven as much by
compatibility with night vision equipment as the human eye.
Just exactly how much improvement is blue/green over red? Does the
difference amount to anything more that picking the fly poop from the
pepper, or are we dealing with an unquantifiable "coolness factor"?
Rick Girard
On Mon, Sep 6, 2010 at 10:04 PM, RV7ASask <rv7alamb@sasktel.net> wrote:
<rv7alamb@sasktel.net>
>>This is an interesting dimmer. =EF=BDDoes it have the noise
problems that Bob was writing about?
I am just finishing installing the radios so I can't tell you about
noise problems at this time. More to follow.
Weighing in on the color of the light. I said earlier 'Stick with
White.' I think both Mr Boeing and Mr Airbus have opted for white in the
cockpit and I think they got it right.
David
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| Subject: | Thermally robust PM rectifier/regulators |
At 09:45 PM 9/6/2010, you wrote:
>Bob, all, mention is made of the John Deere rectifier/regulator as a
>substitute for the Jabiru unit, however, as I recall, the JD unit is
>rather pricey, too. Has anyone investigated the Harley Davidson
>rec/reg? Can be had for at least two output levels and they're
>relatively inexpensive at $35 to $50. Just a thought.
Similarly, I have no hard data on the JD regulators.
My references were based on numerous successful applications
of the JD device on the larger PM alternators popular
with the Corvair engine guys. Further, the JD has
the APPEARANCE of thermal robustness . . . larger
enclosure and more fin area.
The REAL comparison of any regulator's performance is to
get temperature data on critical internal parts
under various operating configurations. Unfortunately,
it's very unlikely that we'll get such data. The
next best data is a max operating temperature for
the R/R case as offered here . . .
http://www.bandc.biz/pdfs/PMR1C_outline_REV_D.pdf
The alternative is to rely on anecdotal successes
or to start from scratch and design a new R/R
where getting the numbers is part of the development
process.
Are you aware of any installations flying that use
the HD parts?
Bob . . .
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| Subject: | Re: dim able strip LED lighting |
Excellent research material. I work on Part 121 Airliners and your
below post seems consistent with what is being done up in their cockpits
(Flight decks). My darkroom days are way in the past and images of the
damage of red light left too long on either film or paper are still
remembered as damaging.
Being able to dim the intensity and use of the most pleasing hue seem
important to me. Thank You. Hope your Marine contract serves you well.
John Cox
do not archive
________________________________
From: owner-aeroelectric-list-server@matronics.com on behalf of Jim
Wickert
Sent: Tue 9/7/2010 7:51 AM
Subject: RE: AeroElectric-List: Re: dim able strip LED lighting
Jim Wickert here, I have been following this thread and have the
following to put up for added fodder. We have a Government Marine
contract which we are working on that has a section for Night
Illumination of Instrumentation and we are doing the scope research now.
Below is some interesting information and food for thought. At this
time our general consensus is Soft White Flood of panels? We have not
released our findings to our customer however. Take care sorry for the
amount of text but this is only a snip of the 13 page findings.
FLITELite Light Color, Intensity & Night Vision:
Pilots have a choice of FLITELite colors - NVIS White (more information
on NVIS White <http://www.flitelite.com/isite/nvis.htm> ), Soft White
that is NVIS friendly, Green, Red and Blue. The best light choice is
NVIS White, followed by soft white, for a light that will protect your
central night vision and provide full spectrum light. Green and Blue
will protect central night vision as well, but blues and greens will
disappear with this color of light - something for a pilot to consider
prior to use. Red is also available, which will protect peripheral night
vision, but not central vision as well as the soft white, blue and
green. Red's on charts will also not be visible with red light, another
consideration for the pilot to consider when making a color choice.
The eyes are comprised of Rods and Cones. We hear people talk about Rods
being for night vision, and Cones for day vision, and while they both
have their special attributes, it would be better to classify them in
the aviation environment at Peripheral (Rods) and Central (Cones)
vision. Both rods and cones have a day and night mode, and they both
react to light at different rates, and to have sensitivity to different
light frequencies.
Rods surround the periphery of the eye and are used for peripheral
vision, and night vision. They do not see color, and do not detect
motion. Rods only provide non-color vision at an acuity of 20/200. Rods
are most susceptible to blue light. You never read, or scan your
instruments with your Rods - or your peripheral vision - think about it.
You are reading this article with your central vision - your cones.
Cones are used for color, central vision, with visual acuity of 20/20.
The cones have a focal width of approximately 20 to 30 degrees. Cones
are most susceptible to red light.
Cones are used when you read, day or night. During the day we read with
our cones - during the night we need a light to read - obvious, but it
shatters the red light myth in the aviation cockpit.
So the question is what is the best light that will provide your eyes,
and brain with the best light for reading? The answer is a dim white
light. Look inside any of the new jets, and you will find that the
lighting is white. Military cockpits specify NVIS White
<http://www.flitelite.com/isite/nvis.htm> . NVIS White appears to have a
green tint, but it is a full spectrum light. More on NVIS Compatibility
<http://www.flitelite.com/isite/nvis.htm>
FLITELite is set to a 25 degree field of view to maximize the physiology
of the pilot's eye. But to preserve night vision the intensity of the
light is what matters. By using a full spectrum white light, the full
spectrum light and low reflection reduces the amount of light needed.
The 25 degree field is critical to keep the light out of our peripheral
vision so we can look for traffic, and gauge height when we are making
that perfect night landing.
Under red light, magenta symbols disappear on charts, and during
electrical failures, red markings on instruments and gauges are
unreadable. Blue light will make Blue 100LL fuel disappear.
Unaided night vision even now in the 21st century is still the subject
of some controversy.
For those just looking for an executive answer as to what supplemental
lighting should be used to reduced the recovery time back to night
vision (dark adapted or scotopic) here it is: a fully dimmable white
light! This of course is a very incomplete answer but so are the answers
red or blue-green and you should know why.
Let's start with red, specifically what I will call the red light myth.
I believe the myth started in the photographic darkroom.
Until about 1906 most photosensitive material (plate, film, and paper)
was not very sensitive to red. Some of these orthochromatic materials
are still used. This allowed these materials to be dealt with for a
short time under a relative bright red light because the human eye can
see red if the level is bright enough. The fact that L.E.D.s (having a
number of advantages over other light sources) were economically only
available in red for some time has also help to perpetuate this myth.
As more research about the eye was done it was found that the structure
responsible for very low light vision, the rods, were also not very
sensitive to red.
It was assumed then that like film you could use red light, which is
seen by the red sensitive cones (there are also blue and green sensitive
cones to give color vision), without affecting the rods.
It takes a while for true night vision to be recovered. About 10
minutes for 10%, 30-45 minutes for 80%, the rest may take hours, days,
or a week. The issue is the chemical in the eye, rhodopsin - commonly
called visual purple, is broken down quickly by light. The main issue
then is intensity; color is only an issue because the rods (responsible
for night vision) are most sensitive at a particular color. That color
is a blue-green (507nm) similar to traffic light green (which is this
color for a entirely different reason). It would seem that using the
lowest brightness (using this color) additional light needed for a task
is the best bet to retain this dark adaptation because it allows rods to
function at their best.
Unfortunately there are a number of drawbacks using only night vision.
Among these are:
* The inability to distinguish colors.
* No detail can be seen (about the same as 20/200 vision in daylight).
* That nothing can be seen directly in front of the eyes (no rods in the
center of the retina), you must learn to look about 15-20=B0 off center.
* Only motion can be detected well, therefore you may have to learn to
move your eyes to detect something that doesn't move.
* Objects that aren't moving appear to move (autokinesis). This has
probably led to a number of plane crashes.
If you need to see directly in front of you or see detail you need red.
Like many myths the red light myth has some basis in fact. The red
truth?
Why red? The center 1.5% of your retina (the fovea) which provides you
with most detailed vision is packed almost exclusively with red
sensitive cones.
This is the same area that has no rods and is responsible for the night
blind spot. There are fewer total green sensitive cones than red. The
number of blue sensitive cones is very small compared to green and red.
Which is just as well since the lens in the human eye cannot focus red
and blue at the same time. And using green really only changes
perceived brightness because of the way the signals are processed in our
neural pathways. Unlike a digital camera, more pixels, in this case,
doesn't give us more detail.
Chart showing the distribution of rods vs cones. Note the absence of
rods in the center and the absence of both about 15=B0 away from the the
center toward the nose where the optic nerve passes.
At first glance the tendency would be to pick the hue of red at which we
are most sensitive (566nm) which would make sense except for the real
reason: we don't want to involve the rods. The reason is the rods share
the neural pathways with the cones so that you have this fuzzy image
overriding the detailed one. This effect disappears at slightly higher
mesopic levels which is why white is a good choice for most tasks. Many
people look at the numbers for sensitivity for rods and cones and forget
that in most cases the numbers have been adjusted so that rod peek
sensitive matches cone peak. Rods are in fact sensitive well into the
infrared (not too useful except to know that light you can barely sense
can adversely impact your night vision). The key then is finding a hue
that we can have at a high enough intensity that we can see the detail
we need without activating our rods to the point where they obscure that
detail. Most source say this should be nothing shorter than 650nm.
Experimentation shows a L.E.D. with a peek around 700nm seems to work
best (perceived as a deep red). Note that red may be fatiguing to the
eyes.
Conclusions:
* No matter what your color choice it must be fully adjustable for
intensity.
* If you need the fastest dark adaptation recovery and can adjust to the
limitations, or everyone in your group is using night vision equipment
then blue-green.
* If you must see detail (reading a star chart, or instrument settings)
and can lose peripheral vision (see note 1)
<http://stlplaces.com/night_vision_red_myth/#note1> , then a very long
wavelength red at a very low level. Red really only has an advantage at
very low levels (were the night blind spot is very obvious).
* A general walking around light so that you don't trip over the tripod,
knock over equipment or bump into people, then blue-green with enough
red added to get rid of the night blind spot, or maybe just use white.
Blue-green at higher brightness also works very well and at a lower
intensity than white.
* If you need to see color and detail then likely the best choice is the
dimmest white light for the shortest amount of time.
* If you are in the military you must follow their rules; hopefully they
will have a good course in unassisted night vision.
* If you are a pilot and say you only fly in the day, you should be
aware of the problems of night vision and should consider a basic
(ground) course in night flying.
* If you wonder why no one else has drawn these conclusions look at the
dashboard of most cars. The markings are large, the pointers are large
and an orange-red (a compromise, for certain "color blind" persons) and
at night it is edge lit with blue-green filtered fully intensity
adjustable light.
For Best night vision:
* Be sure you are getting enough vitamin A or its precursor
beta-carotene in your diet (needed for the visual purple).
* Green leafy stuff is best followed by vegetables that have an orange
color. Yes that includes carrots but spinach or dark leaf lettuce are
better. It is possible to get too much vitamin A especially as a
supplement.
* Keep up your general health. Smoking is also very bad for night
vision, as are most illegal drugs and some prescription drugs.
* Keep you blood sugar level as even as possible. No meal skipping.
Six small meals are better than three large meals. For carbohydrates
favor starches (potatoes, rice, and bread) over simple sugars (sweets,
alcohol).
* Use dark neutral gray sunglasses, that pass no more that 15% in full
sun, when outside during the day.
True night blindness is rare. Most of what people call night blindness
is either a lack of vitamin A in the diet or a failure to understand the
night blind spot.
Cataracts, even minor ones, increase the effects of glare at night and
the eye's lens does yellow and passes less light as we age which may
contribute to what some call night blindness.
Note: The red filtered light at the intensity most people use is likely
decreasing night vision much more than a properly dimmed white or
blue-green light would!
Note: There are day blind spots also but are in a different position in
each eye so are less of a problem.
Note: Blue-green (also called cyan, turquoise, teal and other names) as
used here is NOT the combination of two colors but is a single
particular hue. I use the most common name for that hue.
Mil-STD 1472F 5.8.2.2 (table XVI) display lighting
Brightness of markings
Condition of use
Lighting Technique *
cd/m2
foot-lamberts
Brightness Adjustment
Indicator reading, dark adaptation necessary
Red flood, indirect, or both, with operator choice
0.07-0.35
(0.02-0.1)
Continuous throughout range
Indicator reading, dark adaptation not necessary but desirable
Red or low-color-temperature white flood, indirect, or both, with
operator choice
0.07-3.5?
(0.02-1.0)
Continuous throughout range
Indicator reading, dark adaptation not necessary
White flood
3.5-70
(1-20)
Fixed or continuous
Panel monitoring, dark adaptation necessary
Red edge lighting, red or white flood, or both, with operator choice
0.07-3.5
(0.02-1.0)
Continuous throughout range
Panel monitoring, dark adaptation not necessary
White flood
35-70
(10-20)
Fixed or continuous
Possible exposure to bright flashes, restricted daylight
White flood
35-70
(10-20)
Fixed
Chart reading, dark adaptation necessary
Red or white flood with operator choice
0.35-3.50
(0.1-1.0)
Continuous throughout range
Chart reading, dark adaptation not necessary
White flood
17-70
(5-20)
Fixed or continuous
* Where detection of ground vehicles or other protected assets by image
intensifier night vision devices must be minimized, blue-green light
(incandescent filament through a filter which passes only wave lengths
shorter than 600 nm) should be used in lieu of red light.
? Possible error in original, read as: 0.07-0.35, likely occurred when
converted to metric.
________________________________
This is intended only as an overview; no warranty of this information is
expressed or implied
________________________________
[Update 17 Nov 2003] I find new myths are springing up. Such as
blue-green L.E.D.s are emitting two colors of light. This is a
mis-understanding of the color name and that this is the most accepted
name for this one color. Another is that blue improves night vision.
While at somewhat higher levels it, of course, is stimulating the rods.
It is not an optimum color. Another long standing myth is that human
visual perception is based on three colors when it is really based on
four. The rods are usually ignored because many people believe,
wrongly, that at the brightness at which we perceive color the rods are
no longer providing our brains with any information. In fact the
perception of brightness is highly influenced by the rods well into the
photopic (bright light) range of vision. Fluorescent lamp manufacturers
have used this knowledge for a long time. "Cool White" lamps have an
additional amount of green phosphor added to make us "see" them as being
brighter! Of course the whole subject of color vision and the variances
thereof (wrongly called "color blindness") will require a number of new
pages even in synopsis form.
A point I forgot to cover is that to help preserve night vision in one
eye the other may be closed or covered if you know you are about to be
exposed to a brighter light, such as from a oncoming vehicle. For
normal observation both eyes should be kept open. If it is difficult to
concentrate on the desired image the eye not being used may be covered
but not closed. Closing affects focus and possibly acuity.
[Update 14 Dec 2003] A very important point barely mentioned in the
original is that human peripheral vision is almost completely rod based!
The implication then is that we cannot see color at the edges of our
vision. If you think we can, try this simple experiment. You will need
a small assortment of color cards (try sheets of construction paper) and
someone to assist you. Sit looking straight ahead while you're
assistant, about 6 to 10 feet away, slowly moves a random color card
into the margin of your vision. Now, while still looking straight
ahead, what color is the card?
This is the second most important factor that has been ignored in the
design of outdoor lighting, the first being glare! However this study
<http://stlplaces.com/cgi/redirect.cgi?http://dmses.dot.gov/docimages/pdf
66/133155_web.pdf> (in pdf), at the U. S. Dept. of Transportation, is a
subjective study of blue tinted headlamps.
[Update 23 Jan 2004] A few random notes to be better integrated into
this document later.
Luminances are approximate and will vary with the individual and
conditions.
Vision luminance rage 1 * 10-6 to 1 * 106 cd/M2
Rods luminance rage 1 * 10-6 to 1 * 103 cd/M2 (may still play a roll
above this range)
Cones luminance rage 1 * 10-3 to 1 * 106 cd/M2
Explain "Purinke shift"
20/20 vision is the ability to resolve 1 minute of arc at 20 feet.
Discuss Ricco's Law.
Discuss afterimages.
LITELite NVIS Compatibility
MIL-STD-3009 was developed by the Department of Defense in February 2001
and superceded MIL-L-85762A. It specifies that NVIS White for crew
cockpit and utility lighting. NVIS Green A is grand fathered into the
cockpit for certain applications, but not for new applications.
The chromacity of NVIS White makes it a full spectrum light even though
is appears to have a green tint. Visible light can be split into the
three primary colors, red, green and blue. The eye needs two primary
colors to see 'white'. NVIS White, in simple terms is blue range through
the green range. NVIS goggles filters allow a thin band of green light
though the lens - so that users can see heads up displays and other
required applications through the goggles.
The level of light with respect to the chromacity is important due to
this leak (filter) in the goggles. Other manufacturers claim to be the
'only authorized' lights produced since they meet a request for proposal
standard. These claims are false - they have never tested FLITELite
products how could they know? FLITELite meets and exceeds non-binding
RFP standards, AND meets the modern, more stringent MIL-STD-3009, which
is a binding requirement specified by the military.
General Aviation pilots can benefit from this technology. This light
spectrum and intensity is perfect for general night vision use as well.
Read MIL-STD-3009
<http://www.flitelite.com/isite/support/MIL_STD_3009.pdf> here.
FLITELite minimizes the crossover zone by using a special combination of
LED's and Filter material. The filter material ensures that the light
greater than 600 nm is not transmitted.
Jim Wickert
Vision #159 "Vision some will have some will not"
Tel 920-467-0219
Cell 920-912-1014
Message 8
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| Subject: | Re: dim able strip LED lighting |
Another good point.
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of John
McMahon
Sent: Tuesday, September 07, 2010 9:30 AM
Subject: Re: AeroElectric-List: Re: dim able strip LED lighting
And remember when the red cockpit lighting made all of the fan markers and
LF ranges mysteriously disappear from our charts on night flights!
On Mon, Sep 6, 2010 at 7:25 PM, Lynn Riggs <riggs_la@yahoo.com> wrote:
I have flown with both, I am a retired Army pilot, and can tell you that the
blue-green lighting has less of an impact on night vision than red and is
easier to read charts with. At lease the blue-green the Army used.
Lynn
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Gerry van
Dyk
Sent: Monday, September 06, 2010 6:43 PM
Subject: RE: AeroElectric-List: Re: dim able strip LED lighting
<gerry.vandyk@shaw.ca>
That is rather curious. Amateur astronomers use red flashlights at night
when looking at their charts, the reason being red light doesn't cause the
eye's iris to close, which kills dark adapted vision. When observing
objects through larger telescopes one can occasionally pick up a blue-green
color in subjects like the Ring Nebula (M57)the reason being the color
receptors in the retina pick up the middle of the visible spectrum (520
nanometer wavelength)at the lowest light levels. I have a suspicion that
this study determined that blue-green is the easiest to see, which is
different than the best color for preserving night vision.
http://www.oneminuteastronomer.com/astro-course-day-5/
I would suggest doing some research into WWII night fighters. For one, the
P-61 Black Widow used red cockpit lighting. Red allows you to look at the
instruments, then look out the window without having to wait for your eyes
to re-adapt to the darkness.
Gerry
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Lynn
Riggs
Sent: September 6, 2010 2:24 PM
Subject: RE: AeroElectric-List: Re: dim able strip LED lighting
White is not good for your night vision. The military has found that a
blue-green light is the best in night operations.
Lynn
==========
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| Subject: | Re: dim able strip LED lighting |
I take Bilberry Extract which was used in WW2 and suggested for
improving rod stimulation. Could be an old wives tale, but I do well
with it. On trick to flying at night is to do it more often. Regardless
of color (yes, some are better than others), choosing the best color
will not automatically improve your night vision. People are always
looking for a magic pill.
One thing I notice is that when I fly more often at night, my vision
becomes more readily sensitive to the light available. In other words,
the third night is better than the first. It=92s the same thing that
happens when I go from the city to hunting in the woods. For the first
few days I never see an animal and then almost magically I begin to see
small changes in the landscape and critters moving about were before not
seen.
I believe they call the process adaptation. So, buy the best color that
suits your needs, but better yet, sleep in Saturday morning and take to
the stars more often.
Glenn,
New Garden, PA
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of John
Cox
Sent: Tuesday, September 07, 2010 11:57 AM
Subject: RE: AeroElectric-List: Re: dim able strip LED lighting
Excellent research material. I work on Part 121 Airliners and your
below post seems consistent with what is being done up in their cockpits
(Flight decks). My darkroom days are way in the past and images of the
damage of red light left too long on either film or paper are still
remembered as damaging.
Being able to dim the intensity and use of the most pleasing hue seem
important to me. Thank You. Hope your Marine contract serves you well.
John Cox
do not archive
________________________________
From: owner-aeroelectric-list-server@matronics.com on behalf of Jim
Wickert
Sent: Tue 9/7/2010 7:51 AM
Subject: RE: AeroElectric-List: Re: dim able strip LED lighting
Jim Wickert here, I have been following this thread and have the
following to put up for added fodder. We have a Government Marine
contract which we are working on that has a section for Night
Illumination of Instrumentation and we are doing the scope research now.
Below is some interesting information and food for thought. At this
time our general consensus is Soft White Flood of panels? We have not
released our findings to our customer however. Take care sorry for the
amount of text but this is only a snip of the 13 page findings.
FLITELite Light Color, Intensity & Night Vision:
Pilots have a choice of FLITELite colors - NVIS White (more information
on NVIS White <http://www.flitelite.com/isite/nvis.htm> ), Soft White
that is NVIS friendly, Green, Red and Blue. The best light choice is
NVIS White, followed by soft white, for a light that will protect your
central night vision and provide full spectrum light. Green and Blue
will protect central night vision as well, but blues and greens will
disappear with this color of light - something for a pilot to consider
prior to use. Red is also available, which will protect peripheral night
vision, but not central vision as well as the soft white, blue and
green. Red's on charts will also not be visible with red light, another
consideration for the pilot to consider when making a color choice.
The eyes are comprised of Rods and Cones. We hear people talk about Rods
being for night vision, and Cones for day vision, and while they both
have their special attributes, it would be better to classify them in
the aviation environment at Peripheral (Rods) and Central (Cones)
vision. Both rods and cones have a day and night mode, and they both
react to light at different rates, and to have sensitivity to different
light frequencies.
Rods surround the periphery of the eye and are used for peripheral
vision, and night vision. They do not see color, and do not detect
motion. Rods only provide non-color vision at an acuity of 20/200. Rods
are most susceptible to blue light. You never read, or scan your
instruments with your Rods - or your peripheral vision - think about it.
You are reading this article with your central vision - your cones.
Cones are used for color, central vision, with visual acuity of 20/20.
The cones have a focal width of approximately 20 to 30 degrees. Cones
are most susceptible to red light.
Cones are used when you read, day or night. During the day we read with
our cones - during the night we need a light to read - obvious, but it
shatters the red light myth in the aviation cockpit.
So the question is what is the best light that will provide your eyes,
and brain with the best light for reading? The answer is a dim white
light. Look inside any of the new jets, and you will find that the
lighting is white. Military cockpits specify NVIS White
<http://www.flitelite.com/isite/nvis.htm> . NVIS White appears to have a
green tint, but it is a full spectrum light. More on NVIS Compatibility
<http://www.flitelite.com/isite/nvis.htm>
FLITELite is set to a 25 degree field of view to maximize the physiology
of the pilot=92s eye. But to preserve night vision the intensity of the
light is what matters. By using a full spectrum white light, the full
spectrum light and low reflection reduces the amount of light needed.
The 25 degree field is critical to keep the light out of our peripheral
vision so we can look for traffic, and gauge height when we are making
that perfect night landing.
Under red light, magenta symbols disappear on charts, and during
electrical failures, red markings on instruments and gauges are
unreadable. Blue light will make Blue 100LL fuel disappear.
Unaided night vision even now in the 21st century is still the subject
of some controversy.
For those just looking for an executive answer as to what supplemental
lighting should be used to reduced the recovery time back to night
vision (dark adapted or scotopic) here it is: a fully dimmable white
light! This of course is a very incomplete answer but so are the answers
red or blue-green and you should know why.
Let=92s start with red, specifically what I will call the red light
myth.
I believe the myth started in the photographic darkroom.
Until about 1906 most photosensitive material (plate, film, and paper)
was not very sensitive to red. Some of these orthochromatic materials
are still used. This allowed these materials to be dealt with for a
short time under a relative bright red light because the human eye can
see red if the level is bright enough. The fact that L.E.D.s (having a
number of advantages over other light sources) were economically only
available in red for some time has also help to perpetuate this myth.
As more research about the eye was done it was found that the structure
responsible for very low light vision, the rods, were also not very
sensitive to red.
It was assumed then that like film you could use red light, which is
seen by the red sensitive cones (there are also blue and green sensitive
cones to give color vision), without affecting the rods.
It takes a while for true night vision to be recovered. About 10
minutes for 10%, 30-45 minutes for 80%, the rest may take hours, days,
or a week. The issue is the chemical in the eye, rhodopsin - commonly
called visual purple, is broken down quickly by light. The main issue
then is intensity; color is only an issue because the rods (responsible
for night vision) are most sensitive at a particular color. That color
is a blue-green (507nm) similar to traffic light green (which is this
color for a entirely different reason). It would seem that using the
lowest brightness (using this color) additional light needed for a task
is the best bet to retain this dark adaptation because it allows rods to
function at their best.
Unfortunately there are a number of drawbacks using only night vision.
Among these are:
* The inability to distinguish colors.
* No detail can be seen (about the same as 20/200 vision in daylight).
* That nothing can be seen directly in front of the eyes (no rods in the
center of the retina), you must learn to look about 15-20=B0 off center.
* Only motion can be detected well, therefore you may have to learn to
move your eyes to detect something that doesn't move.
* Objects that aren't moving appear to move (autokinesis). This has
probably led to a number of plane crashes.
If you need to see directly in front of you or see detail you need red.
Like many myths the red light myth has some basis in fact. The red
truth?
Why red? The center 1.5% of your retina (the fovea) which provides you
with most detailed vision is packed almost exclusively with red
sensitive cones.
This is the same area that has no rods and is responsible for the night
blind spot. There are fewer total green sensitive cones than red. The
number of blue sensitive cones is very small compared to green and red.
Which is just as well since the lens in the human eye cannot focus red
and blue at the same time. And using green really only changes
perceived brightness because of the way the signals are processed in our
neural pathways. Unlike a digital camera, more pixels, in this case,
doesn't give us more detail.
Chart showing the distribution of rods vs cones. Note the absence of
rods in the center and the absence of both about 15=B0 away from the the
center toward the nose where the optic nerve passes.
At first glance the tendency would be to pick the hue of red at which we
are most sensitive (566nm) which would make sense except for the real
reason: we don't want to involve the rods. The reason is the rods share
the neural pathways with the cones so that you have this fuzzy image
overriding the detailed one. This effect disappears at slightly higher
mesopic levels which is why white is a good choice for most tasks. Many
people look at the numbers for sensitivity for rods and cones and forget
that in most cases the numbers have been adjusted so that rod peek
sensitive matches cone peak. Rods are in fact sensitive well into the
infrared (not too useful except to know that light you can barely sense
can adversely impact your night vision). The key then is finding a hue
that we can have at a high enough intensity that we can see the detail
we need without activating our rods to the point where they obscure that
detail. Most source say this should be nothing shorter than 650nm.
Experimentation shows a L.E.D. with a peek around 700nm seems to work
best (perceived as a deep red). Note that red may be fatiguing to the
eyes.
Conclusions:
* No matter what your color choice it must be fully adjustable for
intensity.
* If you need the fastest dark adaptation recovery and can adjust to the
limitations, or everyone in your group is using night vision equipment
then blue-green.
* If you must see detail (reading a star chart, or instrument settings)
and can lose peripheral vision (see note 1)
<http://stlplaces.com/night_vision_red_myth/#note1> , then a very long
wavelength red at a very low level. Red really only has an advantage at
very low levels (were the night blind spot is very obvious).
* A general walking around light so that you don't trip over the tripod,
knock over equipment or bump into people, then blue-green with enough
red added to get rid of the night blind spot, or maybe just use white.
Blue-green at higher brightness also works very well and at a lower
intensity than white.
* If you need to see color and detail then likely the best choice is the
dimmest white light for the shortest amount of time.
* If you are in the military you must follow their rules; hopefully they
will have a good course in unassisted night vision.
* If you are a pilot and say you only fly in the day, you should be
aware of the problems of night vision and should consider a basic
(ground) course in night flying.
* If you wonder why no one else has drawn these conclusions look at the
dashboard of most cars. The markings are large, the pointers are large
and an orange-red (a compromise, for certain "color blind" persons) and
at night it is edge lit with blue-green filtered fully intensity
adjustable light.
For Best night vision:
* Be sure you are getting enough vitamin A or its precursor
beta-carotene in your diet (needed for the visual purple).
* Green leafy stuff is best followed by vegetables that have an orange
color. Yes that includes carrots but spinach or dark leaf lettuce are
better. It is possible to get too much vitamin A especially as a
supplement.
* Keep up your general health. Smoking is also very bad for night
vision, as are most illegal drugs and some prescription drugs.
* Keep you blood sugar level as even as possible. No meal skipping.
Six small meals are better than three large meals. For carbohydrates
favor starches (potatoes, rice, and bread) over simple sugars (sweets,
alcohol).
* Use dark neutral gray sunglasses, that pass no more that 15% in full
sun, when outside during the day.
True night blindness is rare. Most of what people call night blindness
is either a lack of vitamin A in the diet or a failure to understand the
night blind spot.
Cataracts, even minor ones, increase the effects of glare at night and
the eye's lens does yellow and passes less light as we age which may
contribute to what some call night blindness.
Note: The red filtered light at the intensity most people use is likely
decreasing night vision much more than a properly dimmed white or
blue-green light would!
Note: There are day blind spots also but are in a different position in
each eye so are less of a problem.
Note: Blue-green (also called cyan, turquoise, teal and other names) as
used here is NOT the combination of two colors but is a single
particular hue. I use the most common name for that hue.
Mil-STD 1472F 5.8.2.2 (table XVI) display lighting
Brightness of markings
Condition of use
Lighting Technique *
cd/m2
foot-lamberts
Brightness Adjustment
Indicator reading, dark adaptation necessary
Red flood, indirect, or both, with operator choice
0.07-0.35
(0.02-0.1)
Continuous throughout range
Indicator reading, dark adaptation not necessary but desirable
Red or low-color-temperature white flood, indirect, or both, with
operator choice
0.07-3.5=86
(0.02-1.0)
Continuous throughout range
Indicator reading, dark adaptation not necessary
White flood
3.5-70
(1-20)
Fixed or continuous
Panel monitoring, dark adaptation necessary
Red edge lighting, red or white flood, or both, with operator choice
0.07-3.5
(0.02-1.0)
Continuous throughout range
Panel monitoring, dark adaptation not necessary
White flood
35-70
(10-20)
Fixed or continuous
Possible exposure to bright flashes, restricted daylight
White flood
35-70
(10-20)
Fixed
Chart reading, dark adaptation necessary
Red or white flood with operator choice
0.35-3.50
(0.1-1.0)
Continuous throughout range
Chart reading, dark adaptation not necessary
White flood
17-70
(5-20)
Fixed or continuous
* Where detection of ground vehicles or other protected assets by image
intensifier night vision devices must be minimized, blue-green light
(incandescent filament through a filter which passes only wave lengths
shorter than 600 nm) should be used in lieu of red light.
=86 Possible error in original, read as: 0.07-0.35, likely occurred when
converted to metric.
________________________________
This is intended only as an overview; no warranty of this information is
expressed or implied
________________________________
[Update 17 Nov 2003] I find new myths are springing up. Such as
blue-green L.E.D.s are emitting two colors of light. This is a
mis-understanding of the color name and that this is the most accepted
name for this one color. Another is that blue improves night vision.
While at somewhat higher levels it, of course, is stimulating the rods.
It is not an optimum color. Another long standing myth is that human
visual perception is based on three colors when it is really based on
four. The rods are usually ignored because many people believe,
wrongly, that at the brightness at which we perceive color the rods are
no longer providing our brains with any information. In fact the
perception of brightness is highly influenced by the rods well into the
photopic (bright light) range of vision. Fluorescent lamp manufacturers
have used this knowledge for a long time. "Cool White" lamps have an
additional amount of green phosphor added to make us "see" them as being
brighter! Of course the whole subject of color vision and the variances
thereof (wrongly called "color blindness") will require a number of new
pages even in synopsis form.
A point I forgot to cover is that to help preserve night vision in one
eye the other may be closed or covered if you know you are about to be
exposed to a brighter light, such as from a oncoming vehicle. For
normal observation both eyes should be kept open. If it is difficult to
concentrate on the desired image the eye not being used may be covered
but not closed. Closing affects focus and possibly acuity.
[Update 14 Dec 2003] A very important point barely mentioned in the
original is that human peripheral vision is almost completely rod based!
The implication then is that we cannot see color at the edges of our
vision. If you think we can, try this simple experiment. You will need
a small assortment of color cards (try sheets of construction paper) and
someone to assist you. Sit looking straight ahead while you=92re
assistant, about 6 to 10 feet away, slowly moves a random color card
into the margin of your vision. Now, while still looking straight
ahead, what color is the card?
This is the second most important factor that has been ignored in the
design of outdoor lighting, the first being glare! However this study
<http://stlplaces.com/cgi/redirect.cgi?http://dmses.dot.gov/docimages/pdf
66/133155_web.pdf> (in pdf), at the U. S. Dept. of Transportation, is a
subjective study of blue tinted headlamps.
[Update 23 Jan 2004] A few random notes to be better integrated into
this document later.
Luminances are approximate and will vary with the individual and
conditions.
Vision luminance rage 1 * 10-6 to 1 * 106 cd/M2
Rods luminance rage 1 * 10-6 to 1 * 103 cd/M2 (may still play a roll
above this range)
Cones luminance rage 1 * 10-3 to 1 * 106 cd/M2
Explain "Purinke shift"
20/20 vision is the ability to resolve 1 minute of arc at 20 feet.
Discuss Ricco's Law.
Discuss afterimages.
LITELite NVIS Compatibility
MIL-STD-3009 was developed by the Department of Defense in February 2001
and superceded MIL-L-85762A. It specifies that NVIS White for crew
cockpit and utility lighting. NVIS Green A is grand fathered into the
cockpit for certain applications, but not for new applications.
The chromacity of NVIS White makes it a full spectrum light even though
is appears to have a green tint. Visible light can be split into the
three primary colors, red, green and blue. The eye needs two primary
colors to see 'white'. NVIS White, in simple terms is blue range through
the green range. NVIS goggles filters allow a thin band of green light
though the lens - so that users can see heads up displays and other
required applications through the goggles.
The level of light with respect to the chromacity is important due to
this leak (filter) in the goggles. Other manufacturers claim to be the
'only authorized' lights produced since they meet a request for proposal
standard. These claims are false - they have never tested FLITELite
products how could they know? FLITELite meets and exceeds non-binding
RFP standards, AND meets the modern, more stringent MIL-STD-3009, which
is a binding requirement specified by the military.
General Aviation pilots can benefit from this technology. This light
spectrum and intensity is perfect for general night vision use as well.
Read MIL-STD-3009
<http://www.flitelite.com/isite/support/MIL_STD_3009.pdf> here.
FLITELite minimizes the crossover zone by using a special combination of
LED's and Filter material. The filter material ensures that the light
greater than 600 nm is not transmitted.
Jim Wickert
Vision #159 =93Vision some will have some will not=94
Tel 920-467-0219
Cell 920-912-1014
Message 10
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| Subject: | Re: Thermally robust PM rectifier/regulators |
Bob, Not aware of any flying, unless you count the times I've raced my
Shovelhead over Washington Pass from Darlington to Winthrop. I can give a
data point for their robustness. The one on my Vibraglide is rigidly mounted
and has been there for over 20 years.
Rick
On Tue, Sep 7, 2010 at 10:10 AM, Robert L. Nuckolls, III <
nuckolls.bob@aeroelectric.com> wrote:
> nuckolls.bob@aeroelectric.com>
>
> At 09:45 PM 9/6/2010, you wrote:
>
>> Bob, all, mention is made of the John Deere rectifier/regulator as a
>> substitute for the Jabiru unit, however, as I recall, the JD unit is rather
>> pricey, too. Has anyone investigated the Harley Davidson rec/reg? Can be had
>> for at least two output levels and they're relatively inexpensive at $35 to
>> $50. Just a thought.
>>
>
> Similarly, I have no hard data on the JD regulators.
> My references were based on numerous successful applications
> of the JD device on the larger PM alternators popular
> with the Corvair engine guys. Further, the JD has
> the APPEARANCE of thermal robustness . . . larger
> enclosure and more fin area.
>
> The REAL comparison of any regulator's performance is to
> get temperature data on critical internal parts
> under various operating configurations. Unfortunately,
> it's very unlikely that we'll get such data. The
> next best data is a max operating temperature for
> the R/R case as offered here . . .
>
> http://www.bandc.biz/pdfs/PMR1C_outline_REV_D.pdf
>
> The alternative is to rely on anecdotal successes
> or to start from scratch and design a new R/R
> where getting the numbers is part of the development
> process.
>
> Are you aware of any installations flying that use
> the HD parts?
>
>
> Bob . . .
>
>
--
Zulu Delta
Kolb Mk IIIC
582 Gray head
4.00 C gearbox
3 blade WD
Thanks, Homer GBYM
It is not bigotry to be certain we are right; but it is bigotry to be unable
to imagine how we might possibly have gone wrong.
- G.K. Chesterton
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| Subject: | Re: Thermally robust PM rectifier/regulators |
At 12:43 PM 9/7/2010, you wrote:
>Bob, Not aware of any flying, unless you count the times I've raced
>my Shovelhead over Washington Pass from Darlington to Winthrop. I
>can give a data point for their robustness. The one on my Vibraglide
>is rigidly mounted and has been there for over 20 years.
What's the output rating for the alternator . . .
and do you know how heavily you load it?
Bob . . .
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| Subject: | Re: Thermally robust PM rectifier/regulators |
I put an Ultraglide dynamo in a few years back for 32 amp output. I probably
don't load it up much, just lighting and ignition.
Rick
On Tue, Sep 7, 2010 at 1:06 PM, Robert L. Nuckolls, III <
nuckolls.bob@aeroelectric.com> wrote:
> nuckolls.bob@aeroelectric.com>
>
> At 12:43 PM 9/7/2010, you wrote:
>
>> Bob, Not aware of any flying, unless you count the times I've raced my
>> Shovelhead over Washington Pass from Darlington to Winthrop. I can give a
>> data point for their robustness. The one on my Vibraglide is rigidly mounted
>> and has been there for over 20 years.
>>
>
> What's the output rating for the alternator . . .
> and do you know how heavily you load it?
>
>
> Bob . . .
>
>
--
Zulu Delta
Kolb Mk IIIC
582 Gray head
4.00 C gearbox
3 blade WD
Thanks, Homer GBYM
It is not bigotry to be certain we are right; but it is bigotry to be unable
to imagine how we might possibly have gone wrong.
- G.K. Chesterton
Message 13
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| Subject: | Re: dim able strip LED lighting |
Greetings Jim,
I appreciate you sharing the info. Would it be possible to make the
balance of your research available? I certainly understand in you
choose not to, but I thought I'd ask.
Thanks again for making this info available.
do not archive
Raymond Julian
Kettle River, MN
On 09/07/2010 09:51 AM, Jim Wickert wrote:
> Jim Wickert here, I have been following this thread and have the
> following to put up for added fodder. We have a Government Marine
> contract which we are working on that has a section for Night
> Illumination of Instrumentation and we are doing the scope research now.
> Below is some interesting information and food for thought. At this
> time our general consensus is Soft White Flood of panels? We have not
> released our findings to our customer however. Take care sorry for the
> amount of text but this is only a snip of the 13 page findings.
>
> FLITELite Light Color, Intensity & Night Vision:
>
> Pilots have a choice of FLITELite colors - NVIS White (more information
> on NVIS White <http://www.flitelite.com/isite/nvis.htm>), Soft White
> that is NVIS friendly, Green, Red and Blue. The best light choice is
> NVIS White, followed by soft white, for a light that will protect your
> central night vision and provide full spectrum light. Green and Blue
> will protect central night vision as well, but blues and greens will
> disappear with this color of light - something for a pilot to consider
> prior to use. Red is also available, which will protect peripheral night
> vision, but not central vision as well as the soft white, blue and
> green. Red's on charts will also not be visible with red light, another
> consideration for the pilot to consider when making a color choice.
>
> The eyes are comprised of Rods and Cones. We hear people talk about Rods
> being for night vision, and Cones for day vision, and while they both
> have their special attributes, it would be better to classify them in
> the aviation environment at Peripheral (Rods) and Central (Cones)
> vision. Both rods and cones have a day and night mode, and they both
> react to light at different rates, and to have sensitivity to different
> light frequencies.
>
> Rods surround the periphery of the eye and are used for peripheral
> vision, and night vision. They do not see color, and do not detect
> motion. Rods only provide non-color vision at an acuity of 20/200. Rods
> are most susceptible to blue light. You never read, or scan your
> instruments with your Rods - or your peripheral vision - think about it.
> You are reading this article with your central vision - your cones.
>
> Cones are used for color, central vision, with visual acuity of 20/20.
> The cones have a focal width of approximately 20 to 30 degrees. Cones
> are most susceptible to red light.
>
> Cones are used when you read, day or night. During the day we read with
> our cones - during the night we need a light to read - obvious, but it
> shatters the red light myth in the aviation cockpit.
>
> http://www.flitelite.com/isite/images/rcdist.gif
>
> So the question is what is the best light that will provide your eyes,
> and brain with the best light for reading? The answer is a dim white
> light. Look inside any of the new jets, and you will find that the
> lighting is white. Military cockpits specify NVIS White
> <http://www.flitelite.com/isite/nvis.htm>. NVIS White appears to have a
> green tint, but it is a full spectrum light. More on NVIS Compatibility
> <http://www.flitelite.com/isite/nvis.htm>
>
> FLITELite is set to a 25 degree field of view to maximize the physiology
> of the pilots eye. But to preserve night vision the intensity of the
> light is what matters. By using a full spectrum white light, the full
> spectrum light and low reflection reduces the amount of light needed.
> The 25 degree field is critical to keep the light out of our peripheral
> vision so we can look for traffic, and gauge height when we are making
> that perfect night landing.
>
> Under red light, magenta symbols disappear on charts, and during
> electrical failures, red markings on instruments and gauges are
> unreadable. Blue light will make Blue 100LL fuel disappear.
>
> Unaided night vision even now in the 21st century is still the subject
> of some controversy.
>
> For those just looking for an executive answer as to what supplemental
> lighting should be used to reduced the recovery time back to night
> vision (dark adapted or scotopic) here it is: a fully dimmable white
> light! This of course is a very incomplete answer but so are the answers
> red or blue-green and you should know why.
>
> Lets start with red, specifically what I will call the red light myth.
>
> I believe the myth started in the photographic darkroom.
>
> Until about 1906 most photosensitive material (plate, film, and paper)
> was not very sensitive to red. Some of these orthochromatic materials
> are still used. This allowed these materials to be dealt with for a
> short time under a relative bright red light because the human eye can
> see red if the level is bright enough. The fact that L.E.D.s (having a
> number of advantages over other light sources) were economically only
> available in red for some time has also help to perpetuate this myth.
>
> As more research about the eye was done it was found that the structure
> responsible for very low light vision, the rods, were also not very
> sensitive to red.
>
> It was assumed then that like film you could use red light, which is
> seen by the red sensitive cones (there are also blue and green sensitive
> cones to give color vision), without affecting the rods.
>
> It takes a while for true night vision to be recovered. About 10 minutes
> for 10%, 30-45 minutes for 80%, the rest may take hours, days, or a
> week. The issue is the chemical in the eye, rhodopsin - commonly called
> visual purple, is broken down quickly by light. The main issue then is
> intensity; color is only an issue because the rods (responsible for
> night vision) are most sensitive at a particular color. That color is a
> blue-green (507nm) similar to traffic light green (which is this color
> for a entirely different reason). It would seem that using the lowest
> brightness (using this color) additional light needed for a task is the
> best bet to retain this dark adaptation because it allows rods to
> function at their best.
>
> Unfortunately there are a number of drawbacks using only night vision.
>
> Among these are:
>
> * The inability to distinguish colors.
> * No detail can be seen (about the same as 20/200 vision in daylight).
> * That nothing can be seen directly in front of the eyes (no rods in
> the center of the retina), you must learn to look about 15-20 off
> center.
> * Only motion can be detected well, therefore you may have to learn
> to move your eyes to detect something that doesn't move.
> * Objects that aren't moving appear to move (autokinesis). This has
> probably led to a number of plane crashes.
>
> If you need to see directly in front of you or see detail you need red.
> Like many myths the red light myth has some basis in fact. The red truth?
>
> Why red? The center 1.5% of your retina (the fovea) which provides you
> with most detailed vision is packed almost exclusively with red
> sensitive cones.
>
> This is the same area that has no rods and is responsible for the night
> blind spot. There are fewer total green sensitive cones than red. The
> number of blue sensitive cones is very small compared to green and red.
>
> Which is just as well since the lens in the human eye cannot focus red
> and blue at the same time. And using green really only changes perceived
> brightness because of the way the signals are processed in our neural
> pathways. Unlike a digital camera, more pixels, in this case, doesn't
> give us more detail.
>
> rod density vs. conesChart showing the distribution of rods vs cones.
> Note the absence of rods in the center and the absence of both about 15
> away from the the center toward the nose where the optic nerve passes.
>
> At first glance the tendency would be to pick the hue of red at which we
> are most sensitive (566nm) which would make sense except for the real
> reason: we don't want to involve the rods. The reason is the rods share
> the neural pathways with the cones so that you have this fuzzy image
> overriding the detailed one. This effect disappears at slightly higher
> mesopic levels which is why white is a good choice for most tasks. Many
> people look at the numbers for sensitivity for rods and cones and forget
> that in most cases the numbers have been adjusted so that rod peek
> sensitive matches cone peak. Rods are in fact sensitive well into the
> infrared (not too useful except to know that light you can barely sense
> can adversely impact your night vision). The key then is finding a hue
> that we can have at a high enough intensity that we can see the detail
> we need without activating our rods to the point where they obscure that
> detail. Most source say this should be nothing shorter than 650nm.
> Experimentation shows a L.E.D. with a peek around 700nm seems to work
> best (perceived as a deep red). Note that red may be fatiguing to the eyes.
>
> Conclusions:
>
> * No matter what your color choice it must be fully adjustable for
> intensity.
> * If you need the fastest dark adaptation recovery and can adjust to
> the limitations, or everyone in your group is using night vision
> equipment then blue-green.
> * If you must see detail (reading a star chart, or instrument
> settings) and can lose peripheral vision^ (see note 1)
> <http://stlplaces.com/night_vision_red_myth/#note1> , then a very
> long wavelength red at a very low level. Red really only has an
> advantage at very low levels (were the night blind spot is very
> obvious).
> * A general walking around light so that you don't trip over the
> tripod, knock over equipment or bump into people, then blue-green
> with enough red added to get rid of the night blind spot, or maybe
> just use white. Blue-green at higher brightness also works very
> well and at a lower intensity than white.
> * If you need to see color and detail then likely the best choice is
> the dimmest white light for the shortest amount of time.
> * If you are in the military you must follow their rules; hopefully
> they will have a good course in unassisted night vision.
> * If you are a pilot and say you only fly in the day, you should be
> aware of the problems of night vision and should consider a basic
> (ground) course in night flying.
> * If you wonder why no one else has drawn these conclusions look at
> the dashboard of most cars. The markings are large, the pointers
> are large and an orange-red (a compromise, for certain "color
> blind" persons) and at night it is edge lit with blue-green
> filtered fully intensity adjustable light.
>
> For Best night vision:
>
> * Be sure you are getting enough vitamin A or its precursor
> beta-carotene in your diet (needed for the visual purple).
> * Green leafy stuff is best followed by vegetables that have an
> orange color. Yes that includes carrots but spinach or dark leaf
> lettuce are better. It is possible to get too much vitamin A
> especially as a supplement.
> * Keep up your general health. Smoking is also very bad for night
> vision, as are most illegal drugs and some prescription drugs.
> * Keep you blood sugar level as even as possible. No meal skipping.
> Six small meals are better than three large meals. For
> carbohydrates favor starches (potatoes, rice, and bread) over
> simple sugars (sweets, alcohol).
> * Use dark neutral gray sunglasses, that pass no more that 15% in
> full sun, when outside during the day.
>
> True night blindness is rare. Most of what people call night blindness
> is either a lack of vitamin A in the diet or a failure to understand the
> night blind spot.
>
> Cataracts, even minor ones, increase the effects of glare at night and
> the eye's lens does yellow and passes less light as we age which may
> contribute to what some call night blindness.
>
> Note: The red filtered light at the intensity most people use is likely
> decreasing night vision much more than a properly dimmed white or
> blue-green light would!
>
> Note: There are day blind spots also but are in a different position in
> each eye so are less of a problem.
>
> Note: Blue-green (also called cyan, turquoise, teal and other names) as
> used here is NOT the combination of two colors but is a single
> particular hue. I use the most common name for that hue.
>
> *Mil-STD 1472F 5.8.2.2 (table XVI) display lighting*
>
>
>
> Brightness of markings
>
>
>
> Condition of use
>
>
>
> Lighting Technique *
>
>
>
> cd/m^2
>
>
>
> foot-lamberts
>
>
>
> Brightness Adjustment
>
> Indicator reading, dark adaptation necessary
>
>
>
> Red flood, indirect, or both, with operator choice
>
>
>
> 0.07-0.35
>
>
>
> (0.02-0.1)
>
>
>
> Continuous throughout range
>
> Indicator reading, dark adaptation not necessary but desirable
>
>
>
> Red or low-color-temperature white flood, indirect, or both, with
> operator choice
>
>
>
> 0.07-3.5
>
>
>
> (0.02-1.0)
>
>
>
> Continuous throughout range
>
> Indicator reading, dark adaptation not necessary
>
>
>
> White flood
>
>
>
> 3.5-70
>
>
>
> (1-20)
>
>
>
> Fixed or continuous
>
> Panel monitoring, dark adaptation necessary
>
>
>
> Red edge lighting, red or white flood, or both, with operator choice
>
>
>
> 0.07-3.5
>
>
>
> (0.02-1.0)
>
>
>
> Continuous throughout range
>
> Panel monitoring, dark adaptation not necessary
>
>
>
> White flood
>
>
>
> 35-70
>
>
>
> (10-20)
>
>
>
> Fixed or continuous
>
> Possible exposure to bright flashes, restricted daylight
>
>
>
> White flood
>
>
>
> 35-70
>
>
>
> (10-20)
>
>
>
> Fixed
>
> Chart reading, dark adaptation necessary
>
>
>
> Red or white flood with operator choice
>
>
>
> 0.35-3.50
>
>
>
> (0.1-1.0)
>
>
>
> Continuous throughout range
>
> Chart reading, dark adaptation not necessary
>
>
>
> White flood
>
>
>
> 17-70
>
>
>
> (5-20)
>
>
>
> Fixed or continuous
>
>
> * Where detection of ground vehicles or other protected assets by image
> intensifier night vision devices must be minimized, blue-green light
> (incandescent filament through a filter which passes only wave lengths
> shorter than 600 nm) should be used in lieu of red light.
>
> Possible error in original, read as: 0.07-0.35, likely occurred when
> converted to metric.
>
> ------------------------------------------------------------------------
>
> *This is intended only as an overview; no warranty of this information
> is expressed or implied*
>
> ------------------------------------------------------------------------
>
> [Update 17 Nov 2003] I find new myths are springing up. Such as
> blue-green L.E.D.s are emitting two colors of light. This is a
> mis-understanding of the color name and that this is the most accepted
> name for this one color. Another is that blue improves night vision.
> While at somewhat higher levels it, of course, is stimulating the rods.
> It is not an optimum color. Another long standing myth is that human
> visual perception is based on three colors when it is really based on
> four. The rods are usually ignored because many people believe, wrongly,
> that at the brightness at which we perceive color the rods are no longer
> providing our brains with any information. In fact the perception of
> brightness is highly influenced by the rods well into the photopic
> (bright light) range of vision. Fluorescent lamp manufacturers have used
> this knowledge for a long time. "Cool White" lamps have an additional
> amount of green phosphor added to make us "see" them as being brighter!
> Of course the whole subject of color vision and the variances thereof
> (wrongly called "color blindness") will require a number of new pages
> even in synopsis form.
> A point I forgot to cover is that to help preserve night vision in one
> eye the other may be closed or covered if you know you are about to be
> exposed to a brighter light, such as from a oncoming vehicle. For normal
> observation both eyes should be kept open. If it is difficult to
> concentrate on the desired image the eye not being used may be covered
> but not closed. Closing affects focus and possibly acuity.
>
> [Update 14 Dec 2003] A very important point barely mentioned in the
> original is that human peripheral vision is almost completely rod based!
> The implication then is that we cannot see color at the edges of our
> vision. If you think we can, try this simple experiment. You will need a
> small assortment of color cards (try sheets of construction paper) and
> someone to assist you. Sit looking straight ahead while youre
> assistant, about 6 to 10 feet away, slowly moves a random color card
> into the margin of your vision. Now, while still looking straight ahead,
> what color is the card?
>
> This is the second most important factor that has been ignored in the
> design of outdoor lighting, the first being glare! However this study
> <http://stlplaces.com/cgi/redirect.cgi?http://dmses.dot.gov/docimages/pdf66/133155_web.pdf>
> (in pdf), at the U. S. Dept. of Transportation, is a subjective study of
> blue tinted headlamps.
>
> [Update 23 Jan 2004] A few random notes to be better integrated into
> this document later.
> Luminances are approximate and will vary with the individual and conditions.
> Vision luminance rage 1 * 10^-6 to 1 * 10^6 cd/M^2
> Rods luminance rage 1 * 10^-6 to 1 * 10^3 cd/M^2 (may still play a roll
> above this range)
> Cones luminance rage 1 * 10^-3 to 1 * 10^6 cd/M^2
> Explain "Purinke shift"
> 20/20 vision is the ability to resolve 1 minute of arc at 20 feet.
> Discuss Ricco's Law.
> Discuss afterimages.
>
> LITELite NVIS Compatibility
>
> MIL-STD-3009 was developed by the Department of Defense in February 2001
> and superceded MIL-L-85762A. It specifies that NVIS White for crew
> cockpit and utility lighting. NVIS Green A is grand fathered into the
> cockpit for certain applications, but not for new applications.
>
> The chromacity of NVIS White makes it a full spectrum light even though
> is appears to have a green tint. Visible light can be split into the
> three primary colors, red, green and blue. The eye needs two primary
> colors to see 'white'. NVIS White, in simple terms is blue range through
> the green range. NVIS goggles filters allow a thin band of green light
> though the lens - so that users can see heads up displays and other
> required applications through the goggles.
>
> The level of light with respect to the chromacity is important due to
> this leak (filter) in the goggles. Other manufacturers claim to be the
> 'only authorized' lights produced since they meet a request for proposal
> standard. These claims are false - they have never tested FLITELite
> products how could they know? FLITELite meets and exceeds non-binding
> RFP standards, AND meets the modern, more stringent MIL-STD-3009, which
> is a binding requirement specified by the military.
>
> General Aviation pilots can benefit from this technology. This light
> spectrum and intensity is perfect for general night vision use as well.
>
> Read MIL-STD-3009
> <http://www.flitelite.com/isite/support/MIL_STD_3009.pdf> here.
>
> http://www.flitelite.com/isite/images/nvischart.jpg
>
> http://www.flitelite.com/isite/images/range.jpg
>
> FLITELite minimizes the crossover zone by using a special combination of
> LED's and Filter material. The filter material ensures that the light
> greater than 600 nm is not transmitted.
>
> http://www.flitelite.com/isite/images/nvissys.jpg
>
> Jim Wickert
>
> Vision #159 Vision some will have some will not
>
> Tel 920-467-0219
>
> Cell 920-912-1014
>
> *From:* owner-aeroelectric-list-server@matronics.com
> [mailto:owner-aeroelectric-list-server@matronics.com] *On Behalf Of
> *Richard Girard
> *Sent:* Tuesday, September 07, 2010 8:35 AM
> *To:* aeroelectric-list@matronics.com
> *Subject:* Re: AeroElectric-List: Re: dim able strip LED lighting
>
> Using the example of Boeing and Airbus for cockpit lighting in a good
> example of not examining the application before making a decision, IMHO.
> When was the last time an airline crew really needed to have good night
> vision for looking outside the cockpit? Unless you plan on flying on
> instruments from takeoff to touchdown, or very nearly, is this the wise
> choice?
>
> Even using the military, particularly what the helicopter cockpits use,
> is questionable since their decision may have been driven as much by
> compatibility with night vision equipment as the human eye.
>
> Just exactly how much improvement is blue/green over red? Does the
> difference amount to anything more that picking the fly poop from the
> pepper, or are we dealing with an unquantifiable "coolness factor"?
>
> Rick Girard
>
> On Mon, Sep 6, 2010 at 10:04 PM, RV7ASask <rv7alamb@sasktel.net
> <mailto:rv7alamb@sasktel.net>> wrote:
>
> <rv7alamb@sasktel.net <mailto:rv7alamb@sasktel.net>>
>
> >>This is an interesting dimmer. Does it have the noise problems that
> Bob was writing about?
>
> I am just finishing installing the radios so I can't tell you about
> noise problems at this time. More to follow.
>
> Weighing in on the color of the light. I said earlier 'Stick with
> White.' I think both Mr Boeing and Mr Airbus have opted for white in the
> cockpit and I think they got it right.
>
> David
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=311626#311626
>
>
> ==========
> -
> ric-List"
> target="_blank">http://www.matronics.com/Navigator?AeroElectric-List
> ==========
> MS -
> k">http://forums.matronics.com
> ==========
> e -
> -Matt Dralle, List Admin.
> t="_blank">http://www.matronics.com/contribution
> ==========
>
>
> --
>
> Zulu Delta
>
> Kolb Mk IIIC
>
> 582 Gray head
>
> 4.00 C gearbox
>
> 3 blade WD
>
> Thanks, Homer GBYM
>
> It is not bigotry to be certain we are right; but it is bigotry to be
> unable to imagine how we might possibly have gone wrong.
>
> - G.K. Chesterton
>
> * *
>
> * *
>
> **
>
> **
>
> **
>
> **
>
> **
>
> **
>
> *http://www.matronics.com/Navigator?AeroElectric-List*
>
> **
>
> **
>
> **
>
> *http://forums.matronics.com*
>
> **
>
> **
>
> **
>
> **
>
> *http://www.matronics.com/contribution*
>
> **
>
> * *
>
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| Subject: | Re: dim able strip LED lighting |
Raymond,
I will when we have finalized this section formally with our customer and they
have signed off on that part of the project. We have a IP Intellectual Property
clause issues on each item that we need to get sign off for. But yes once
this is signed off I will send this out to the mass.
Jim Wickert
Vision #159 "Vision some will have it some will not"
Tel 920-467-0219
Cell 920-912-1014
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of rayj
Sent: Tuesday, September 07, 2010 6:57 PM
Subject: Re: AeroElectric-List: Re: dim able strip LED lighting
Greetings Jim,
I appreciate you sharing the info. Would it be possible to make the
balance of your research available? I certainly understand in you
choose not to, but I thought I'd ask.
Thanks again for making this info available.
do not archive
Raymond Julian
Kettle River, MN
On 09/07/2010 09:51 AM, Jim Wickert wrote:
> Jim Wickert here, I have been following this thread and have the
> following to put up for added fodder. We have a Government Marine
> contract which we are working on that has a section for Night
> Illumination of Instrumentation and we are doing the scope research now.
> Below is some interesting information and food for thought. At this
> time our general consensus is Soft White Flood of panels? We have not
> released our findings to our customer however. Take care sorry for the
> amount of text but this is only a snip of the 13 page findings.
>
> FLITELite Light Color, Intensity & Night Vision:
>
> Pilots have a choice of FLITELite colors - NVIS White (more information
> on NVIS White <http://www.flitelite.com/isite/nvis.htm>), Soft White
> that is NVIS friendly, Green, Red and Blue. The best light choice is
> NVIS White, followed by soft white, for a light that will protect your
> central night vision and provide full spectrum light. Green and Blue
> will protect central night vision as well, but blues and greens will
> disappear with this color of light - something for a pilot to consider
> prior to use. Red is also available, which will protect peripheral night
> vision, but not central vision as well as the soft white, blue and
> green. Red's on charts will also not be visible with red light, another
> consideration for the pilot to consider when making a color choice.
>
> The eyes are comprised of Rods and Cones. We hear people talk about Rods
> being for night vision, and Cones for day vision, and while they both
> have their special attributes, it would be better to classify them in
> the aviation environment at Peripheral (Rods) and Central (Cones)
> vision. Both rods and cones have a day and night mode, and they both
> react to light at different rates, and to have sensitivity to different
> light frequencies.
>
> Rods surround the periphery of the eye and are used for peripheral
> vision, and night vision. They do not see color, and do not detect
> motion. Rods only provide non-color vision at an acuity of 20/200. Rods
> are most susceptible to blue light. You never read, or scan your
> instruments with your Rods - or your peripheral vision - think about it.
> You are reading this article with your central vision - your cones.
>
> Cones are used for color, central vision, with visual acuity of 20/20.
> The cones have a focal width of approximately 20 to 30 degrees. Cones
> are most susceptible to red light.
>
> Cones are used when you read, day or night. During the day we read with
> our cones - during the night we need a light to read - obvious, but it
> shatters the red light myth in the aviation cockpit.
>
> http://www.flitelite.com/isite/images/rcdist.gif
>
> So the question is what is the best light that will provide your eyes,
> and brain with the best light for reading? The answer is a dim white
> light. Look inside any of the new jets, and you will find that the
> lighting is white. Military cockpits specify NVIS White
> <http://www.flitelite.com/isite/nvis.htm>. NVIS White appears to have a
> green tint, but it is a full spectrum light. More on NVIS Compatibility
> <http://www.flitelite.com/isite/nvis.htm>
>
> FLITELite is set to a 25 degree field of view to maximize the physiology
> of the pilots eye. But to preserve night vision the intensity of the
> light is what matters. By using a full spectrum white light, the full
> spectrum light and low reflection reduces the amount of light needed.
> The 25 degree field is critical to keep the light out of our peripheral
> vision so we can look for traffic, and gauge height when we are making
> that perfect night landing.
>
> Under red light, magenta symbols disappear on charts, and during
> electrical failures, red markings on instruments and gauges are
> unreadable. Blue light will make Blue 100LL fuel disappear.
>
> Unaided night vision even now in the 21st century is still the subject
> of some controversy.
>
> For those just looking for an executive answer as to what supplemental
> lighting should be used to reduced the recovery time back to night
> vision (dark adapted or scotopic) here it is: a fully dimmable white
> light! This of course is a very incomplete answer but so are the answers
> red or blue-green and you should know why.
>
> Lets start with red, specifically what I will call the red light myth.
>
> I believe the myth started in the photographic darkroom.
>
> Until about 1906 most photosensitive material (plate, film, and paper)
> was not very sensitive to red. Some of these orthochromatic materials
> are still used. This allowed these materials to be dealt with for a
> short time under a relative bright red light because the human eye can
> see red if the level is bright enough. The fact that L.E.D.s (having a
> number of advantages over other light sources) were economically only
> available in red for some time has also help to perpetuate this myth.
>
> As more research about the eye was done it was found that the structure
> responsible for very low light vision, the rods, were also not very
> sensitive to red.
>
> It was assumed then that like film you could use red light, which is
> seen by the red sensitive cones (there are also blue and green sensitive
> cones to give color vision), without affecting the rods.
>
> It takes a while for true night vision to be recovered. About 10 minutes
> for 10%, 30-45 minutes for 80%, the rest may take hours, days, or a
> week. The issue is the chemical in the eye, rhodopsin - commonly called
> visual purple, is broken down quickly by light. The main issue then is
> intensity; color is only an issue because the rods (responsible for
> night vision) are most sensitive at a particular color. That color is a
> blue-green (507nm) similar to traffic light green (which is this color
> for a entirely different reason). It would seem that using the lowest
> brightness (using this color) additional light needed for a task is the
> best bet to retain this dark adaptation because it allows rods to
> function at their best.
>
> Unfortunately there are a number of drawbacks using only night vision.
>
> Among these are:
>
> * The inability to distinguish colors.
> * No detail can be seen (about the same as 20/200 vision in daylight).
> * That nothing can be seen directly in front of the eyes (no rods in
> the center of the retina), you must learn to look about 15-20 off
> center.
> * Only motion can be detected well, therefore you may have to learn
> to move your eyes to detect something that doesn't move.
> * Objects that aren't moving appear to move (autokinesis). This has
> probably led to a number of plane crashes.
>
> If you need to see directly in front of you or see detail you need red.
> Like many myths the red light myth has some basis in fact. The red truth?
>
> Why red? The center 1.5% of your retina (the fovea) which provides you
> with most detailed vision is packed almost exclusively with red
> sensitive cones.
>
> This is the same area that has no rods and is responsible for the night
> blind spot. There are fewer total green sensitive cones than red. The
> number of blue sensitive cones is very small compared to green and red.
>
> Which is just as well since the lens in the human eye cannot focus red
> and blue at the same time. And using green really only changes perceived
> brightness because of the way the signals are processed in our neural
> pathways. Unlike a digital camera, more pixels, in this case, doesn't
> give us more detail.
>
> rod density vs. conesChart showing the distribution of rods vs cones.
> Note the absence of rods in the center and the absence of both about 15
> away from the the center toward the nose where the optic nerve passes.
>
> At first glance the tendency would be to pick the hue of red at which we
> are most sensitive (566nm) which would make sense except for the real
> reason: we don't want to involve the rods. The reason is the rods share
> the neural pathways with the cones so that you have this fuzzy image
> overriding the detailed one. This effect disappears at slightly higher
> mesopic levels which is why white is a good choice for most tasks. Many
> people look at the numbers for sensitivity for rods and cones and forget
> that in most cases the numbers have been adjusted so that rod peek
> sensitive matches cone peak. Rods are in fact sensitive well into the
> infrared (not too useful except to know that light you can barely sense
> can adversely impact your night vision). The key then is finding a hue
> that we can have at a high enough intensity that we can see the detail
> we need without activating our rods to the point where they obscure that
> detail. Most source say this should be nothing shorter than 650nm.
> Experimentation shows a L.E.D. with a peek around 700nm seems to work
> best (perceived as a deep red). Note that red may be fatiguing to the eyes.
>
> Conclusions:
>
> * No matter what your color choice it must be fully adjustable for
> intensity.
> * If you need the fastest dark adaptation recovery and can adjust to
> the limitations, or everyone in your group is using night vision
> equipment then blue-green.
> * If you must see detail (reading a star chart, or instrument
> settings) and can lose peripheral vision^ (see note 1)
> <http://stlplaces.com/night_vision_red_myth/#note1> , then a very
> long wavelength red at a very low level. Red really only has an
> advantage at very low levels (were the night blind spot is very
> obvious).
> * A general walking around light so that you don't trip over the
> tripod, knock over equipment or bump into people, then blue-green
> with enough red added to get rid of the night blind spot, or maybe
> just use white. Blue-green at higher brightness also works very
> well and at a lower intensity than white.
> * If you need to see color and detail then likely the best choice is
> the dimmest white light for the shortest amount of time.
> * If you are in the military you must follow their rules; hopefully
> they will have a good course in unassisted night vision.
> * If you are a pilot and say you only fly in the day, you should be
> aware of the problems of night vision and should consider a basic
> (ground) course in night flying.
> * If you wonder why no one else has drawn these conclusions look at
> the dashboard of most cars. The markings are large, the pointers
> are large and an orange-red (a compromise, for certain "color
> blind" persons) and at night it is edge lit with blue-green
> filtered fully intensity adjustable light.
>
> For Best night vision:
>
> * Be sure you are getting enough vitamin A or its precursor
> beta-carotene in your diet (needed for the visual purple).
> * Green leafy stuff is best followed by vegetables that have an
> orange color. Yes that includes carrots but spinach or dark leaf
> lettuce are better. It is possible to get too much vitamin A
> especially as a supplement.
> * Keep up your general health. Smoking is also very bad for night
> vision, as are most illegal drugs and some prescription drugs.
> * Keep you blood sugar level as even as possible. No meal skipping.
> Six small meals are better than three large meals. For
> carbohydrates favor starches (potatoes, rice, and bread) over
> simple sugars (sweets, alcohol).
> * Use dark neutral gray sunglasses, that pass no more that 15% in
> full sun, when outside during the day.
>
> True night blindness is rare. Most of what people call night blindness
> is either a lack of vitamin A in the diet or a failure to understand the
> night blind spot.
>
> Cataracts, even minor ones, increase the effects of glare at night and
> the eye's lens does yellow and passes less light as we age which may
> contribute to what some call night blindness.
>
> Note: The red filtered light at the intensity most people use is likely
> decreasing night vision much more than a properly dimmed white or
> blue-green light would!
>
> Note: There are day blind spots also but are in a different position in
> each eye so are less of a problem.
>
> Note: Blue-green (also called cyan, turquoise, teal and other names) as
> used here is NOT the combination of two colors but is a single
> particular hue. I use the most common name for that hue.
>
> *Mil-STD 1472F 5.8.2.2 (table XVI) display lighting*
>
>
>
> Brightness of markings
>
>
>
> Condition of use
>
>
>
> Lighting Technique *
>
>
>
> cd/m^2
>
>
>
> foot-lamberts
>
>
>
> Brightness Adjustment
>
> Indicator reading, dark adaptation necessary
>
>
>
> Red flood, indirect, or both, with operator choice
>
>
>
> 0.07-0.35
>
>
>
> (0.02-0.1)
>
>
>
> Continuous throughout range
>
> Indicator reading, dark adaptation not necessary but desirable
>
>
>
> Red or low-color-temperature white flood, indirect, or both, with
> operator choice
>
>
>
> 0.07-3.5
>
>
>
> (0.02-1.0)
>
>
>
> Continuous throughout range
>
> Indicator reading, dark adaptation not necessary
>
>
>
> White flood
>
>
>
> 3.5-70
>
>
>
> (1-20)
>
>
>
> Fixed or continuous
>
> Panel monitoring, dark adaptation necessary
>
>
>
> Red edge lighting, red or white flood, or both, with operator choice
>
>
>
> 0.07-3.5
>
>
>
> (0.02-1.0)
>
>
>
> Continuous throughout range
>
> Panel monitoring, dark adaptation not necessary
>
>
>
> White flood
>
>
>
> 35-70
>
>
>
> (10-20)
>
>
>
> Fixed or continuous
>
> Possible exposure to bright flashes, restricted daylight
>
>
>
> White flood
>
>
>
> 35-70
>
>
>
> (10-20)
>
>
>
> Fixed
>
> Chart reading, dark adaptation necessary
>
>
>
> Red or white flood with operator choice
>
>
>
> 0.35-3.50
>
>
>
> (0.1-1.0)
>
>
>
> Continuous throughout range
>
> Chart reading, dark adaptation not necessary
>
>
>
> White flood
>
>
>
> 17-70
>
>
>
> (5-20)
>
>
>
> Fixed or continuous
>
>
> * Where detection of ground vehicles or other protected assets by image
> intensifier night vision devices must be minimized, blue-green light
> (incandescent filament through a filter which passes only wave lengths
> shorter than 600 nm) should be used in lieu of red light.
>
> Possible error in original, read as: 0.07-0.35, likely occurred when
> converted to metric.
>
> ------------------------------------------------------------------------
>
> *This is intended only as an overview; no warranty of this information
> is expressed or implied*
>
> ------------------------------------------------------------------------
>
> [Update 17 Nov 2003] I find new myths are springing up. Such as
> blue-green L.E.D.s are emitting two colors of light. This is a
> mis-understanding of the color name and that this is the most accepted
> name for this one color. Another is that blue improves night vision.
> While at somewhat higher levels it, of course, is stimulating the rods.
> It is not an optimum color. Another long standing myth is that human
> visual perception is based on three colors when it is really based on
> four. The rods are usually ignored because many people believe, wrongly,
> that at the brightness at which we perceive color the rods are no longer
> providing our brains with any information. In fact the perception of
> brightness is highly influenced by the rods well into the photopic
> (bright light) range of vision. Fluorescent lamp manufacturers have used
> this knowledge for a long time. "Cool White" lamps have an additional
> amount of green phosphor added to make us "see" them as being brighter!
> Of course the whole subject of color vision and the variances thereof
> (wrongly called "color blindness") will require a number of new pages
> even in synopsis form.
> A point I forgot to cover is that to help preserve night vision in one
> eye the other may be closed or covered if you know you are about to be
> exposed to a brighter light, such as from a oncoming vehicle. For normal
> observation both eyes should be kept open. If it is difficult to
> concentrate on the desired image the eye not being used may be covered
> but not closed. Closing affects focus and possibly acuity.
>
> [Update 14 Dec 2003] A very important point barely mentioned in the
> original is that human peripheral vision is almost completely rod based!
> The implication then is that we cannot see color at the edges of our
> vision. If you think we can, try this simple experiment. You will need a
> small assortment of color cards (try sheets of construction paper) and
> someone to assist you. Sit looking straight ahead while youre
> assistant, about 6 to 10 feet away, slowly moves a random color card
> into the margin of your vision. Now, while still looking straight ahead,
> what color is the card?
>
> This is the second most important factor that has been ignored in the
> design of outdoor lighting, the first being glare! However this study
> <http://stlplaces.com/cgi/redirect.cgi?http://dmses.dot.gov/docimages/pdf66/133155_web.pdf>
> (in pdf), at the U. S. Dept. of Transportation, is a subjective study of
> blue tinted headlamps.
>
> [Update 23 Jan 2004] A few random notes to be better integrated into
> this document later.
> Luminances are approximate and will vary with the individual and conditions.
> Vision luminance rage 1 * 10^-6 to 1 * 10^6 cd/M^2
> Rods luminance rage 1 * 10^-6 to 1 * 10^3 cd/M^2 (may still play a roll
> above this range)
> Cones luminance rage 1 * 10^-3 to 1 * 10^6 cd/M^2
> Explain "Purinke shift"
> 20/20 vision is the ability to resolve 1 minute of arc at 20 feet.
> Discuss Ricco's Law.
> Discuss afterimages.
>
> LITELite NVIS Compatibility
>
> MIL-STD-3009 was developed by the Department of Defense in February 2001
> and superceded MIL-L-85762A. It specifies that NVIS White for crew
> cockpit and utility lighting. NVIS Green A is grand fathered into the
> cockpit for certain applications, but not for new applications.
>
> The chromacity of NVIS White makes it a full spectrum light even though
> is appears to have a green tint. Visible light can be split into the
> three primary colors, red, green and blue. The eye needs two primary
> colors to see 'white'. NVIS White, in simple terms is blue range through
> the green range. NVIS goggles filters allow a thin band of green light
> though the lens - so that users can see heads up displays and other
> required applications through the goggles.
>
> The level of light with respect to the chromacity is important due to
> this leak (filter) in the goggles. Other manufacturers claim to be the
> 'only authorized' lights produced since they meet a request for proposal
> standard. These claims are false - they have never tested FLITELite
> products how could they know? FLITELite meets and exceeds non-binding
> RFP standards, AND meets the modern, more stringent MIL-STD-3009, which
> is a binding requirement specified by the military.
>
> General Aviation pilots can benefit from this technology. This light
> spectrum and intensity is perfect for general night vision use as well.
>
> Read MIL-STD-3009
> <http://www.flitelite.com/isite/support/MIL_STD_3009.pdf> here.
>
> http://www.flitelite.com/isite/images/nvischart.jpg
>
> http://www.flitelite.com/isite/images/range.jpg
>
> FLITELite minimizes the crossover zone by using a special combination of
> LED's and Filter material. The filter material ensures that the light
> greater than 600 nm is not transmitted.
>
> http://www.flitelite.com/isite/images/nvissys.jpg
>
> Jim Wickert
>
> Vision #159 Vision some will have some will not
>
> Tel 920-467-0219
>
> Cell 920-912-1014
>
> *From:* owner-aeroelectric-list-server@matronics.com
> [mailto:owner-aeroelectric-list-server@matronics.com] *On Behalf Of
> *Richard Girard
> *Sent:* Tuesday, September 07, 2010 8:35 AM
> *To:* aeroelectric-list@matronics.com
> *Subject:* Re: AeroElectric-List: Re: dim able strip LED lighting
>
> Using the example of Boeing and Airbus for cockpit lighting in a good
> example of not examining the application before making a decision, IMHO.
> When was the last time an airline crew really needed to have good night
> vision for looking outside the cockpit? Unless you plan on flying on
> instruments from takeoff to touchdown, or very nearly, is this the wise
> choice?
>
> Even using the military, particularly what the helicopter cockpits use,
> is questionable since their decision may have been driven as much by
> compatibility with night vision equipment as the human eye.
>
> Just exactly how much improvement is blue/green over red? Does the
> difference amount to anything more that picking the fly poop from the
> pepper, or are we dealing with an unquantifiable "coolness factor"?
>
> Rick Girard
>
> On Mon, Sep 6, 2010 at 10:04 PM, RV7ASask <rv7alamb@sasktel.net
> <mailto:rv7alamb@sasktel.net>> wrote:
>
> <rv7alamb@sasktel.net <mailto:rv7alamb@sasktel.net>>
>
> >>This is an interesting dimmer. Does it have the noise problems that
> Bob was writing about?
>
> I am just finishing installing the radios so I can't tell you about
> noise problems at this time. More to follow.
>
> Weighing in on the color of the light. I said earlier 'Stick with
> White.' I think both Mr Boeing and Mr Airbus have opted for white in the
> cockpit and I think they got it right.
>
> David
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=311626#311626
>
>
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>
> --
>
> Zulu Delta
>
> Kolb Mk IIIC
>
> 582 Gray head
>
> 4.00 C gearbox
>
> 3 blade WD
>
> Thanks, Homer GBYM
>
> It is not bigotry to be certain we are right; but it is bigotry to be
> unable to imagine how we might possibly have gone wrong.
>
> - G.K. Chesterton
>
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