by Rod_outbak » 08 May 2018, 10:45 am
My experience; your mileage will likely differ...
For road use, avoid flood or diffusion LED lights. You want driving or spot lights. Flood lights produce lots of incredibly bright light near the car, but very little any distance further out.
[I think they call it 'Blooming'].
Flood/diffusion lights work great on machinery, but at 100 kph, you find you are outrunning the light.
Overall wattage isnt that useful in LED's; the wattage per emitter is more important. Pretty sure you can get 1w, 3w, 5w and 10w emitters these days, and most LED lights are made up of a mix of these.
Lumens is often mis-quoted, and plenty of suppliers actually quote 'Theoretical Lumens' (I know Sun-Yee does for some models).
As a (VERY rough) guide, a standard 100w halogen light punches out roughly 1700 lumens, but the size/shape of the reflector decides just how well that light is projected down the road. I've got some of the smaller Sun-Yee lights that are supposed to be at least 3500 lumens each, and they were worse than the vehicle lights.
The 18.9" Stedi Light bar I bought for the niece seems to be well made, and I'd guess it's punching out pretty close to the lumens Stedi promise.
Lux is possibly going to give more of an indication how far the light reaches (1 lux @ x metres)
Size of emitter(and their reflector) seems to make the most difference on how far LED lights will project. Best light projection seems to come from 5w or 10w emitters. The Sun-Yee lights I have here seem to be all 1w & 3w emitters, and the reflectors are tiny. Eye-watering lights in close, but couldnt see a roo 50 metres up the road.
From my experience, you want a good pool of light on the road a few hundred metres away. You want some light outside that, but not enough to overload signs. The Sun-Yee lightbars I bought in Feb are all "sign overload", and barely able to see a roo at 50 metres. The Stedi bar I bought my niece seems to be mostly light down the road, with a lesser amount out to the sides.
Also consider a combination of lights. Maybe a light bar for the pool down the road, and then a couple of smaller ones to project out to the sides? Reason is there arent many bars that can give that spread of light (I dont think the curved ones are going to work all that well for most people).
I dont have much experience with round LED lights; I'll be interested to see how they perform.
My best light setup is on my landcruiser ute. 2 Lightforce XGT Halogens providing the light down the road. 2 Cibie Oscar MX (small) halogens lighting up the shoulders of the road. And then two 6" Rigid light bars to provide close-in light; fanning out to roughly 45 degrees off the line of the road.
That car would have to be the best car I've used for driving at night; you dont get tired from trying to pick out the stationary roos all the time.
I'm in the process of changing over the Landcruiser wagon to soemthing better than the 2 tired Lightforce 240 Blitz halogens it currently has. If I can fit it in, I'm going a pair of Hella Rallye 4000 halogens for spots, and a 20" light bar sitting above them, which will do the road-shoulders and kamikaze attacks.
A final thought. Light temperature (colour) makes an impact on how well light penetrates dust and fog. Yellow lights are used in fog, as they penetrate further. We have both a halogen shooting spotlight, as well as an HID one. The halogen is much yellower, compared to the HID, but seems to penetrate further in dusty conditions. The HID seems to 'bloom' a lot more, and so you find any airborne dust gets lit up by the much brighter light, means you cant see as far in the same conditions.
LED bars are usually whiter than halogens, though elder brother thought he'd seen that someone (Lightforce?) were now offering LED lights with different colour temps, and you could pick both a halogen and an LED with very similar colour temps.
As I said; my 2 cents.
Cheers,
Rod.
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Sharing the extreme love with cats in Outback QLD