Question about colour temperature

[Swedpat]

I have experienced how much better warmer tints are for seeing details of objects with brown and green colour than with cool tints. The new "neutral white"-LEDs are great in this respect. Also they are very comfortable and feel more natural for the eyes. But NATURAL WHITE? In my opinion NO. In the same way the cool white is blue tinted I find the neutral white is brown or beige tinted.

I read that the sun has a colour temperature of 5500 Kelvin, which is considered as the true white tint. A cool white LED has around 6000K and a neutral around 4300K. My wondering is if it's impossible to produce a 5500K LED? If it's not, is it possible to approach the colour temperature of the sun more than the LEDs are today?
I suppose my question is stupid and that the manufacturers would have produced the sun-tinted light if they could...

Regards, Patric

 

[DimeRazorback]

I don't find my M60W brown or beige at all :shrug:

I just find it warm...

Maybe it has something to do with the fact that they are too close together to justify selling/making. So they went with a 'larger' difference??

:candle:

 

[Swedpat]

DimeRazorback,

Certainly, I have not seen all "natural-white" LEDs. But my Fenix TK20 I find is clearly beige tinted. Even without any comparison it will never appear as real white when shining at a white surface. Very comfortable and pleasant tint, anyway.

Regards, Patric

 

[DimeRazorback]

I get what you mean now... I wasn't talking about white wall hunting

But when I am white wall hunting I would have to agree with your original statement!

I'm having a shocker today :laughing:

 

[LEDninja]

Check out the McGizmo Sundrop. McGizmo has his own subforum.

To match the sun you need high CRI in addition to the correct colour temperature.

 

[Mjolnir]

The tint is not everything. Like LEDninja said, the color rendering index of LEDs is lower than that of the sun, in that they do not output all of the visible wavelengths of light like the sun does. Incans have a CRI of 100, but their tint is well below 5500K. However, you get better color rendition than even a warm tinted LED. Apparently LEDs have CRI's in the 70 range. A high pressure sodium light (like street lights) only has a CRI of 24, which is horrible for determining the color of objects.

 

[Light Sabre]

I read that the sun has a colour temperature of 5500 Kelvin, which is considered as the true white tint. A cool white LED has around 6000K and a neutral around 4300K. My wondering is if it's impossible to produce a 5500K LED? If it's not, is it possible to approach the colour temperature of the sun more than the LEDs are today?
I suppose my question is stupid and that the manufacturers would have produced the sun-tinted light if they could...

Regards, Patric

I have a bit of a problem understanding understanding the 5500k temp of sunlight as it appears on the earth's surface. I borrowed a colorimeter from a coworker to see what degrees kelvin CFL that I liked the best (4100k) . I pointed it at the sun and got the 5500k reading. Was just reading an article on Wikipedia Sun - Wikipedia, the free encyclopedia and it said that the sun's surface temperature was 5780k. But when sunlight light goes thru the earth's atmosphere, the light at the blue end of the spectrum is scattered by the earth's atmosphere (this is what makes the sky blue) and because of that the sun appears yellow from the earth's surface. So as I understand it, at the earths surface we're dealing with yellow sunlight + the blue skylight which gives us the 5500k reading. I need to borrow the colorimeter again and see what color just the yellow sunlight is (no blue skykight). Here in Boulder Colorado, in the summer objects outside look normal. In the winter, the sun is lower in the sky and is more yellow because of that which makes objects outside have a yellowish cast/tint to them. That's one thing I don't like about the winters here. So why do CFL's above 4100k (pure white light to me) appear to have such a horrible blue tint to them when 5500k is supposed to be white light?

 

[Swedpat]

Thank you all for your inputs!

Actually it's not long time ago when I thought that the sun really has a yellow tint. At many paintings people (often children) use to paint the sun yellow. The reason I understand is because the sun at sunsets appears as yellow because of the atmosphere. The colour temperature then drops.
When I first time read that sun has the most white light I became surprised. One light I experience as the true white are a common flourescent lamp.
These really seems to be whiter than as well LEDs and incans, in comparison an incan seems to be yellow and a LED seems to be bluish.

I think we all know that a cold LED which use to look like the whitest of white at white objects, becomes unveiled as blue tinted when compared to any incan light.
If I understand it right the true neutral white is the tint which will never be experienced as neither yellow or blue, undependent of other comparing light sources?

Regards, Patric

 

[xenonk]

So why do CFL's above 4100k (pure white light to me) appear to have such a horrible blue tint to them when 5500k is supposed to be white light?

It's mostly perception. Compared to a 2700K incandescent light fixture, even a neutral 4300K source will look bluish, especially if you're accustomed to bulbs. There are other factors at play as well, such as the spectral distribution of the light source and the fact that CCT is a scale with only one axis. You could have light that is obviously green-tinted but falls on 5500K anyway.

Ideally you would compare directly to sunlight, but that tends to overpower everything and is difficult to bottle for a double-blind test.

If I understand it right the true neutral white is the tint which will never be experienced as neither yellow or blue, undependent of other comparing light sources?

Never say never. It may appear tinted anyway depending on what you were expecting.

 

[Yoda4561]

Yep, try this, go into a pitch black room, wait for nightfall, close the blinds, use a bathroom with no windows whatever. Give your eyes 5 or 10 minutes to adjust to the darkness, now flip on a neutral white LED... my guess is it won't look pink, tan, or beige at all. If we were all still using incan house lighting they would look brilliant, almost bluish white in comparison. With 6500K "daylight" fluorescent bulbs most folks are used to nowadays, neutral white LED's do look pinkish or a bit beige tinted.

 

[Wiggle]

I find that my 5A and 5B tinted lights only look tinted when shone directly on white walls, yet they look totally natural on anything of mixed color. I heard a theory that this is because these emitters are well balanced in all areas except for cyan which means that they look pinkish on white walls but good otherwise.

Recently a built a light fixture using some natural-white, high-CRI SSC P4s for my bedroom and the light is very pleasing.

 

[xenonk]

I heard a theory that this is because these emitters are well balanced in all areas except for cyan which means that they look pinkish on white walls but good otherwise.

There's a big hole in the spectral output between green and blue (cyan region) that accounts for much of the LED's ~25ish missing CRI. High CRI emitters are better about this because they try to fill in that cyan gap.

Most white LEDs have the same gap regardless of CCT, though. What you're seeing on a warmer emitter is the tint from additional phosphor overpowering the blue the diode naturally emits.

It's a close enough approximation for most things, but when you're emitting unevenly, white surfaces are very good at letting you know.

 

[Cataract]

I was told by a visual insection specialist that ours eyes see better with lighting of a 5300K color when indoors

 

[Tekno_Cowboy]

There's been quite a few threads on this subject recently. I have many of them linked in the modding thread in my sigline.

To the OP: I think you've got Natural confused with Warm. Natural and Neutral are pretty much the same thing. "Warm" tends to be the group that winds up with a brown/beige tint.