Who is liking the warm white luxeons?

[Potto]

I've tried out one of the original violet tinged Luxeons, a pea geen one and a warm white on several "normal" type people. Without exception the warm white came out as the preferred light source as ordinary light, the easiest on the eye for viewing things and perceiving colour correctly. The closest to sunlight or flourescent lighting. These were people who have no interest in LED's, or true white or perfect colour rendering. I've got to admit for reading by at night I find it the most relaxing or easiest to view with LED I've used so far.

PS has anyone used the 1 watt low cost Luxeon look alike?

 

[jtr1962]

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Wylie said:
Check this out guys! How long did man live by fire light before LED or what have you came about. I believe the spectrum is more related to fire light then color endurance and incandescent lamps have been mocking this same trait by quirk maybe.


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Maybe, but then we used to dress in loin cloths, get water from rivers, hunt animals with spears for food, and live to 40 (if we were lucky). I'll take modern living (and light sources that look more like the sun than fire) any day. Our eyes are designed for a solar-like spectrum, and our night vision seems to work better at higher color temps as well (i.e. bluish moonlight). I don't think we've had enough time to evolve any evolutionary preference for candlelight. Maybe if the sun were a red giant our visual system would be biased towards incandescent-type light.

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Its funny how tests have been done in Las Vegas and the higher interests of visitors would be drawn to the warm white type of spectrum ranging in through the orange and red then any others.


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Las Vegas is a tourist trap, and much of the crowd there tends to be older folks who grew up with incandescents (old habits die hard). While yellow-orange light might be fine for sitting around a camp fire and such, I certainly wouldn't want to do any work under it. Incandescents have always given me headaches. Whites just don't look white under incandescent, and I think my brain continually hunting for a "white point" to no avail is what causes this. Plants look sickly, blues look like purple, people look reddish (I don't find red skin tones flattering), etc. And then there's the fact that rooms end up looking different at night, so frequently you have to decorate for either sunlight or incandescent light as colors look very different under each. High-color temperature lighting avoids this. I think you get my point. I personally don't care what other people use in their homes, but I really dislke the fact that I can't buy CFLs in home stores in the color temperatures I like because of the silly, arbitrary way the general public is fixated on incandescent lighting. I hope the situation changes by the time LED bulb replacements are available. I'm willing to guess many of the kids growing up today with white LED keychain lights and the like will actually prefer higher color temperature lighting enough so that there is at least a choice, or perhaps it will be the only choice (vengeance is sweet, isn't it /ubbthreads/images/graemlins/smile.gif). For what it's worth, most people actually do prefer sunlight to any kind of artificial light, so if LEDs can duplicate sunlight exactly I might get my wish.

 

[Wylie]

Me Too!

 

[jtr1962]

[ QUOTE ]
Potto said:
I've tried out one of the original violet tinged Luxeons, a pea geen one and a warm white on several "normal" type people. Without exception the warm white came out as the preferred light source as ordinary light, the easiest on the eye for viewing things and perceiving colour correctly. The closest to sunlight or flourescent lighting.


[/ QUOTE ]
You compared a warm white Luxeon to bad cool-white Luxeons. Try using something like a Q3 or something close to the Planckian locus with the new binning system. The results might differ, and they may be skewed by the poorer color rendering of the cool-whites anyway. For what it's worth, I'm thinking if the warm-whites aim for a CCT of ~3300K then they most certainly do not imitate most common household incandescent lighting, but rather are closer to a high color rendering neutral-white 3500K fluorescent tube or to a high-temp halogen lamp, both of which are halfway decent alternatives. I'd have to see one in person to make a fairer comparison to incandescent and other lighting sources. Now try your experiment with an incandescent vs. a warm-white Luxeon and see which comes out on top. I think the somewhat higher CCT luxeon will win out. And then maybe try the warm-white LS vs. a decent cool-white LS. I think you'll find at least some, if not a majority, like the cool-white better, especially among younger people.

 

[Wylie]

Well I have no argument for better lack of temrs anyone please? /ubbthreads/images/graemlins/tongue.gif

 

[SilverFox]

I found an interesting bit of information while looking at the Welch Allyn web site.

Their surgical procedure solid state head lamp is rated at a color temperature of 5500 K,

"With a color temperature of 5500 Kelvin, this light supplies bright, white, shadow-free light allowing the end user to see tissue characteristics without distortion."

It seems like this would be a reasonable goal for our lighting needs.

Tom

 

[Big_Ed]

Well, I haven't tried a warm white luxeon, but I like the color of incandescent lights more than LED's, not that I don't like LED's. It's just that I'm used to natural light that come from our YELLOW sun. Natural light is not white on this planet. It's yellow. A very bright yellow, but yellow nonetheless. I don't mind white lights, like fluorescents, but it's not like sunlight. That's why we were always told not to look at a car you were thinking of buying under fluorescent lights. It will look different under natural sunlight. This is not an assault on LED's or anyone who likes them. I like them too. It's just that everyone seems to think that LED's put out a "natural white" light. It doesn't seem natural to me. Again, it's not bad, just not my preference. Just my 2 cents.

 

[jtr1962]

[ QUOTE ]
Big_Ed said:
It's just that I'm used to natural light that come from our YELLOW sun. Natural light is not white on this planet. It's yellow. A very bright yellow, but yellow nonetheless. I don't mind white lights, like fluorescents, but it's not like sunlight. That's why we were always told not to look at a car you were thinking of buying under fluorescent lights.

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Here is a little article about color temperature which dispels the myth that the sun is yellow. The yellow look of the sun is an optical illusion. The sky is blue, and if you put a white light source next to a blue light source then the white light source will look yellow. It's all a matter of your eye's white point adjusting for different color temperatures. For example, a cool white (4100K) fluorescent tube will look blue next to a neutral white (3500K) fluorescent tube. Try putting the same tube next to a 5000K tube and it will look yellow. I've tried this and can personally vouch for the results. In case you think the sun is yellow hold up an incandescent flashlight (these are generally as white as incandescent bulbs get) next to the sun at noon, and see how yellow the bulb looks. Even late and early in the day the bulb will still look yellow. It is only towards sunset and sunrise that an incandescent bulb will really look like the sun. Of course, I respect your preference for incandescent type lighting as this is a personal, subjective thing. I simply wished to dispel once and for all the little myths floating around that "the sun is yellow" and "halogen light is most like the sun". About the closest we've come to producing light like the sun are with full-spectrum 5000K to 5500K fluorescent tubes, and even those have spectral gaps. In time LEDs may duplicate the solar spectrum exactly. Also, I need to point out that the solar spectrum isn't a constant as it varies with season, time of day, latitude, and air pollution. However, for practical purposes most attempts to duplicate sunlight are based on the solar spectrum at high noon at the equator (approximately a blackbody at 5500K). Most inhabited latitudes may experience average color temperatures a few hundred to a 1000K less than this due to the indirect angle of sunlight, but it's safe to say that incandescents aren't even close to sunlight other than being close to a point source like the sun is (maybe that's another reason the myth persists).

Thinking some more about the warm white Luxeons, the specified CCT of 3300K is probably closer to a projector lamp or a short-lifetime flashlight bulb than to what we usually use in our households (2400K to 2800K), and in my opinion probably looks a heck of a lot better. As I said, I would have to do a side by side comparison. 3300K lighting is borderline tolerable for me, so I can see where these may have uses despite my personal preference for something around 5000K. The more typical 2400K to 2800K of common household incandescents is absolutely horrible, and I'm glad Lumileds didn't even attempt to duplicate that. Come to think of it, their amber LS would be pretty close to those. /ubbthreads/images/graemlins/wink.gif

 

[Big_Ed]

jtr1962, Interesting article. However, it seems to me that incandescent bulbs make things appear more natural to my naked eye, plain and simple. Maybe my eyes are different than other people's, and I'm sure that my preference is partially due to what I'm used to seeing. IMHO, incandescent lights still look more like natural sunlight to me, whether or not the color temp is different between the two.

 

[EvilLithiumMan]

[ QUOTE ]
jtr1962 said:
[ QUOTE ]
Big_Ed said:
It's just that I'm used to natural light that come from our YELLOW sun. Natural light is not white on this planet. It's yellow. A very bright yellow, but yellow nonetheless. I don't mind white lights, like fluorescents, but it's not like sunlight. That's why we were always told not to look at a car you were thinking of buying under fluorescent lights.

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Here is a little article about color temperature which dispels the myth that the sun is yellow. The yellow look of the sun is an optical illusion.


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On Monday, Oct 27th, my morning sky was thick with grey smoke as So. California burned. The smoke was so thick that the rising sun was not visible to the naked eye. But the sun was visible to my video camera:

As for medical imagery, many diseases and conditions can be diagnosed by tissue color. Decades ago, doctors realized that for color photographs to have any comparative value, they would all have to be taken using a fixed reference for color temperature and they choose 5500 kelvin.

 

[Big_Ed]

With cameras, I think things look different than with the naked eye. To my naked eyes incandescent looks more natural. I don't want to get into an argument about it. It's just my opinion, and my preference, that's all.

 

[jtr1962]

[ QUOTE ]
Big_Ed said:
With cameras, I think things look different than with the naked eye. To my naked eyes incandescent looks more natural. I don't want to get into an argument about it. It's just my opinion, and my preference, that's all.

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It may have to do with the eye's ability to adjust it's "white point" depending upon the light source. I've noticed this myself when I can walk into a supermarket lit with 3000K tubes which looked distinctly yellow from outside. After a few minutes the tubes look less yellow to me. I think your preference has more to do with your brain than your eyes. Your brain simply feels more comfortable adjusting to a white point typical of incandescent lighting. On the other hand, I'm utterly incapable of feeling comfortable with anything less than about 3500K. My brain just can't make the adjustment, and whites look yellow under even halogen lighting to me. I also find color temps much above 6500K equally distracting as white starts to look too blue. I'm most comfortable at about 5000K. Obviously my preferences leave incandescent lighting out, although its very poor efficiency and non-diffuse nature also make it undesireable. The higher CRI of incandescents may also have something to do with your personal preference as most fluorescent lighting has some spectral gaps (although it is getting better and better in that regard, and the best fluoro lamps can have a CRI over 95). Have you even seen or tried really good high-color temp fluorescent lighting? Many people who say they hate fluorescent have only used poor CRI warm or cool whites on a flickering magnetic ballast. Full-spectrum tubes on a electronic ballast are in a league of their own compared to those.

As I mentioned previously, lighting preference is strictly a personal choice, and there is really no right or wrong for what people use in their homes. My primary beef with widespread use of incandescents has more the do with the horrible efficiency than with the color temp. I don't care what people use in their homes, but I don't think people should be using something for general lighting which gets an efficiency of 8 to 20 lm/W when alternatives exist in the same color temps which get 60 to 90 lm/W. And in public spaces, I think lighting designers shouldn't use anything warmer than about 3500K. This is a good compromise between warm and cool lighting, and some of us just feel very uncomfortable with the warmer, incandescent type lighting of 3000K tubes. Personally, I would like to see full-spectrum 5000K in all public spaces as this mixes well with sunlight, but cost constraints probably prevent this. I think by and large, however, the general public would love it.

 

[NewsFlash]

What, no beam shots from anybody? /ubbthreads/images/graemlins/wink.gif

Evidently those who have bought them like them, I've not seen any for sale on B/S/T~Lights. Anyway, it seems the Sandwich Shoppe has sold quite a few in the last week or so. /ubbthreads/images/graemlins/popcorn.gif