[FrancisK7]

I have a project I am working on in which the various things I need to photograph are lit by LED both white and red (red at 6000k) but I can't seem to color balance no matter what I try.

What am I missing?

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Last edited by FrancisK7; 12-22-2012 at 11:32 PM.

[JinDesu]

If I remember correctly, LED light is very specialized light in that it only puts out a small range of color. It makes white balancing very very difficult. The small range of color means that shifting the white balance cold or warm practically removes all light from the scene.

[Miguel]

red (red at 6000k)

I'm a little confused. 6000k is a little cooler than daylight, like a cloudy day. Perhaps if you described or attached a photo of the lighting setup it would be more helpful. See if you can borrow an incidental color meter to get a value reading.

M

[excanonfd]

Manually white balance on a white card/paper under the shooting lighting condition, the surest way I know of obtaining correct white balance under mixed lighting conditions.

[Anvh]

Like said LED light put out a narrow range of coloured light, you can make white appear white but some colours will always be muted simply because the LED does not output those colours.
You might be able to make a colour profile just for led light to boost the saturation of some colours, for the rest there is nothing you can do about it.

[Bob from Aus]

Anyone out there with some real knowledge of physics? Something does not sound logical about this discussion but I don't know enough to put my finger on it. White light is made up of all colours. If there is a problem then it will have a colour cast that can usually be adjusted.

I am reasonably sure that LEDs can be made to output different colour temperatures, so you should find out the color temp and adjust the camera accordingly.

I think FrancisK7 may still in the dark.

[JinDesu]

It depends on how the white of the LED is produced, but white LEDs should allow for the same white balance as white fluorescents. It's the other LED type lights that are hellish to work with.

An examples of how LED lights play havoc:

The overall scene is already hard to shoot, but the bright green LED source on the left side made it difficult to balance anything. Reducing the green saturation left me with practically nothing (because the green LED only outputs green), so I couldn't do that.

Also note the intense blue LED on the speaker. Changing white balance causes that blue to either get darker or disappear as white.

[Lowell Goudge]

Anyone out there with some real knowledge of physics? Something does not sound logical about this discussion but I don't know enough to put my finger on it. White light is made up of all colours. If there is a problem then it will have a colour cast that can usually be adjusted.

I am reasonably sure that LEDs can be made to output different colour temperatures, so you should find out the color temp and adjust the camera accordingly.

I think FrancisK7 may still in the dark.

Pure white light is described as a broad sprecrum of colors emitted from a black body. The color temperature refers to the temperature of the emitting body, the cooler it is, the more reds, the hotter it is the more blues.

As others have noted, LEDs and other high efficiency lights are somewhat monochromatic, producing very narrow bands of colors. This makes it hard to remove color casts because you can't easily shift the entire spectrum, as there isn't one.

[Stone G.]

- - --White light is made up of all colours. If there is a problem then it will have a colour cast that can usually be adjusted.

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I'm not really a physicist, but I'll dare give it a try anyway:

What others have said is correct. Incandescent lamps emit light by means of a glowing wire of metal (tungsten/wolfram) in a continous spectrum. All colours (wavelenghts) are there, but with different weights.

Energy saving bulbs, flourescent ligt tubes and LEDs only emit light in discrete wavelenghts and not in a continous spectrum. Manufacturers strive to make the light look "natural" to the human eye, but sensors may "see" the light output differently, because their spectral sensitivities differ from that of the human eye. What looks properly balanced to us does not look properly balanced to the sensor.

I use LEDs quite a lot for macro photograhy and have found that the best results are obtained - as also suggested by Bob - in the post processing. But not all LEDs are equal, and difficulties in obtaining an acceptable balance may vary.

[Na Horuk]

buy a small rainbow flag, take a shot of it and then use a normal white balance and try to make the individual colours appear right by playing with the individual colour hue/saturation/brightness.
Or just set camera WB to CTE and say its artistic, that photography is not a document, but a representation, which in turn is always an interpretation, affected by the camera, the software, the viewer.. instead of fighting it, accept it as part of modern culture.

lol or just bring your own light/diffused flash and use set WB according to that light

[Anvh]

This might help

Any truly color accurate LED panels out there? - Lighting - Cinematography.com

[tim60]

This is a recent problem because LEDs produce light by fundamentally different principles than any of the other sources, and it will grow witht he move for LED use in normal lighting, and also the fashion for coloured lighting in commercial places now. The different production principles results in the spectrum of LED light being totally different than the assumptions which underly the colour balance difference, so the standard controls for colour balance in PP applications do not fit. This is really a challenge to the SW makers to develop new spectrum manipulation tools that can deal with the problems.My worst example was at an overseas wedding in a street at night illuminated by a combination of curly flouro lights (somewhat yellow), and various street signs on shop fronts (all colours), vehicle headlamps, street lights, in some places light spill from halogens illuminating astage, and the worst of the lot: LED traffic lights.

What we need is a PP application which enables us to set notch filters to remove the narrow bandwidth of LED sources with controllable cut, and adjustable centre frequency. This is a very different kind of colour balance adjustment compared with the typical colour temperature re-profile.

[Miguel]

The color temperature refers to the temperature of the emitting body, the cooler it is, the more reds, the hotter it is the more blues.

You've got this reversed. Cooler=more blue; warmer=more red.

See.

M

[Lowell Goudge]

You've got this reversed. Cooler=more blue; warmer=more red.

See.

M

Actually no. Lower body temperature emits more red, hotter more blue. The real confusion comes in when we talk about Warm and cold in photos, blue speeds colder, but you get blues with higher color temperatures. Red seems warmer, but it is actually lower color temperatures

[jbinpg]

Lowell is correct:

Star Spectral Classification

I think the photographic meaning of colour temperature is more related to a psychological relationship with people, e.g., moving closer to a warm reddish fire.

Jack