[quote="rv10(at)colohan.com"]On Thu, Nov 5, 2009 at 9:07 PM, XeVision wrote:
> LED still has a long way to go to compete with HID as a landing light. This
is true in terms of total lumens and reach (distance).
>
I'm curious:
a) how many lumens are typical HID landing lights? The newest Cree emitters can put out 1000 lumens per emitter, and hooking up more than one of these emitters into a single unit is pretty easy. I have a 900 lumen 2-emitter bike headlight (from brlights.com (http://brlights.com)), and it is impressively bright, able to illuminate most of my backyard.
b) besides lumens, what determines reach? I would have thought it would be a simple
combination of the amount of light energy, and the beam shape (aka, reflector
design). Are there other variables involved? Do certain colour temperatures
tend to illuminate further?
Chris
> [b]
For a good landing light to reach out 1000 ft or more you must be able collimate
(sp) the light. Something that so far cannot be done so well or easily with
LED. With a high output LED you must maintain control of the junction temps. LED's
dont perform all that well with parabolic reflectors.
35 watt (bulb watts) HID at 4200K 3200 lumens, 50 watts HID (bulb watts) ~5500
lumens, 75 watt HID (bulb watts) 8000+ lumens.
--------
LED still has a long way to go to compete with HID as a landing light. This is
true in terms of total lumens and reach (distance).
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=271312#271312
