TORCH_BOY
Flashlight Enthusiast
Both in there own rights
For instance, depth, 3-dimensionality, and contrast are all affected, and for target acquisition - or even detailed rendering of one's environment, these are very important areas.
I prefer Xenon incan to LED for color rendering. This might not seem like a big deal, but be aware that the inferior color rendering of LEDs have practical consequences. For instance, depth, 3-dimensionality, and contrast are all affected, and for target acquisition - or even detailed rendering of one's environment, these are very important areas. Incans simply render the target area under the light better. Also, incans cut through fog far better than LEDs do. I use an incan for bump-in-the-night and emergency instances, and I use LEDs for everyday use when runtime and low battery replacement frequency are more important.
The reason is that most LEDs are still deficient in reds. They have improved a long way, in that respect however. The ones that look warmer yellowish are better, but the problem is that they are based on a blue emitter, that uses a yellow-green phosphor. In the case of the warm white, more yellow-green phosphor is used, so the light might look yellow, but those phosphors still don't release a lot of red like the incandescent light. It is possible to use two phosphors -- a separate red and green. That would solve the color rendering problem completely, but right now the whole marketing goal is who can come up with the most lumens, and a two-phosphor design would likely hurt the efficiency as the eyes are a lot more sensitive to yellow-green light than red light. I do think this will eventually happen though, as LED start to be used for more things where color rendering matters.just to digress a little..
why do incans provide better colour/depth rendition? i do see the difference for myself, but cant quite explain why.
is it because they are more 'yellow'? if so then yellow tinted led bins should provide the same benefit?
The backscattering has more to do with the excess of spill (your first point) than the color of the LEDs. My LEDs that use optics, or very deep reflectors perform much, much better in the fog. Also, lights with a lot of spill consequently have weaker hotspots, so that means you'll be trying to observe a target with less light reaching it, through a veil of fog lit up by bright spill. The issue with the blue I believe has more to do with the fact that the eyes are generally a lot more sensitive to blue light in the dark -- so the backscattered blue light is more of an irritant than backscattered warm white lightAnother possible explanation for the throw is the beam pattern of LEDs: because most LEDs throw light forward instead of around like a hot wire, less light is caught in the reflector and more light escapes as spill.
Yet another explanation I've read here is stronger backscattering of the strong blue light component in LEDs (incans are weak in that component). I'm not ready to believe that without a more thorough scientific explanation / calculation. For example: consider fog consisting of 10 um droplets and light of 500 nm wavelength, the droplets are still quite a bit bigger (20 times) than the wavelength of the light, so there shouldn't be a strong frequency dependent scattering effect.
Based on what I've read here, many of the LED fans here are converted from incandescent so they have tried the other technology. So have I. Fact is LED got me interested in lighting again. Back when I had more time I used to do model railroading. I may still again at some time in the future. As much as I liked the way things looked lit up the drawbacks of incandescent bulbs just plain made me give up on lighting models. Here's the long list of reasons why:I think that this is the case with some members here at CPF. "I prefer LEDs." "I like incandescents." Fine, I'm sure you do. But have you really tried to honestly appreciate the other technology for what it has to offer? For the LED fans, are you willing to except that you might, you just might, find light at warmer colors pleasurable to look at? You may have a hang-up on associating high quality with just the perfect optical tint. Should you revise this preconception, you might find that you could quite enjoy incandescents. Same goes for the runtime issue. To the incandescent lovers, is the greater flexibility and runtime offered by LEDs truly not something you can appreciate and enjoy, should only you accept the look of LED light for what it is, and not expect the warm rendering of an incandescent?
Even though LED appeals to me as more high-tech, even not counting its other advantages, I actually wish someone would develop some filament material which can burn at 4000K or 5000K or even higher. I would probably be one of the first to embrace it, especially if it had decent life, as it would solve one of the existing problems with LEDs-lack of ability to adjust color temperature. While RGB LEDs may in time solve this problem, the control circuitry to do so while ensuring color balance will be complex. With a hypothetical 5000K filament material you can vary color temperature from 5000K down to whatever you want just by lowering the drive current/voltage. And by it's nature a 5000K hotwire, perhaps with a reflecting IR/UV coating, could top 100 lm/W. Since brightness increases to the fourth power of absolute temperature, it would also be over 5 times brighter than a 3300K hotwire.JTR1962, it sounds like you've given incans a good run, and found ways to modify your LED experience to get many of the same benifits. So for you, Incans may not be the way to go.