Low Energy Photography

[lars_bergquist]

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Has anybody anything to say about colour balancing problems with low energy lamps? The classical tungsten lamps will soon be proscribed all over the EU. How do we cope?

 

The old man from the Age of Kerosene Lamps

[Guest John66]

Even the same lamp causes colour shifts from frame to frame, so it is very tough to find a solution to the problem.

 

Also, if you get one colour properly balanced in post, another colour wanders off in an unpleasant direction.

 

The answer: convert to black and white

[giordano]

Time for Lippmann's interferential process (older than Lars himself!) to come into its own?

[AlanG]

Those light do not put out a continuous spectrum of energy. So even if the overall balance looks pretty good, some colors will be dull and off. I see this more and more in new homes.

[USA road racer]

I think the only thing one can do is to do a WB reading for each shot as the light differs. I use a Colorright WB device & measure & set the light for the shot in difficult light. With this device, I place it to the lens & aim in the direction of the subject then set the cameras WB. Get great shots this way under difficult lighting conditions.

[andit]

Hi Lars,

 

You could use a Gossen Colormeter 3F (GOSSEN Foto- und Lichtmesstechnik - Belichtungsmesser, Blitzbelichtungsmesser, Luxmeter, Digipro F, Mavolux, Mavospot, Mavomonitor, Mavomax, Mavo-spot, Mavo-Max, Farbtemperatur-Messer, Exposure Meter, Flashmeter, Leuchtdichte-Messung, Light Meter, co). Works in much the same way as an exposure meter, except it will measure the temperature of daylight, artificial light, tungsten, halogen, fluorescent light etc. Gives you the exact K value of the light a that moment. The motion picture people use these meters all the time with the white balance being absolutely critical. Don't know about the price, but this would certainly be an option.

 

Andreas

[giordano]

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Hi Lars,

 

You could use a Gossen Colormeter 3F (GOSSEN Foto- und Lichtmesstechnik - Belichtungsmesser, Blitzbelichtungsmesser, Luxmeter, Digipro F, Mavolux, Mavospot, Mavomonitor, Mavomax, Mavo-spot, Mavo-Max, Farbtemperatur-Messer, Exposure Meter, Flashmeter, Leuchtdichte-Messung, Light Meter, co). Works in much the same way as an exposure meter, except it will measure the temperature of daylight, artificial light, tungsten, halogen, fluorescent light etc. Gives you the exact K value of the light a that moment. The motion picture people use these meters all the time with the white balance being absolutely critical. Don't know about the price, but this would certainly be an option.

 

Up to a point. The problem with fluorescent light (compact or otherwise) is precisely that it makes colours appear different in relation to each other than they do when illuminated by a black-body source (e.g. an incandescent light or sunlight) of the same apparent colour temperature. Hence the common experience that if you tweak an image to get some colours right others will get worse. A colour temperature meter, however good, cannot eliminate that.

 

In fact, a fluorescent light doesn't have a real color temperature as such. The manufacturer's figure, if any, is a "correlated color temperature" - the color temperature of incandescent light that to human eyes best matches the light from the fluorescent source, and a color temperature meter will produce a more or less similar reading depending on the number of colours it measures and the characteristics of its filters.

[AlanG]

Up to a point. The problem with fluorescent light (compact or otherwise) is precisely that it makes colours appear different in relation to each other than they do when illuminated by a black-body source (e.g. an incandescent light or sunlight) of the same apparent colour temperature. Hence the common experience that if you tweak an image to get some colours right others will get worse. A colour temperature meter, however good, cannot eliminate that.

 

In fact, a fluorescent light doesn't have a real color temperature as such. The manufacturer's figure, if any, is a "correlated color temperature" - the color temperature of incandescent light that to human eyes best matches the light from the fluorescent source, and a color temperature meter will produce a more or less similar reading depending on the number of colours it measures and the characteristics of its filters.

 

 

This is exactly right. The simulation of a kelvin temperature is made by stimulating phosphors with a light source that contains strong color spikes in very narrow frequencies - typically green, yellow, or blue. The color spikes remain and effect the image despite the simulated kelvin temperature. And the amount of trouble you have varies depending on the light.

 

This is the same with digital as it was on film. Except it is easier to correct for it with digital as you can dial in an overall color balance and then tweak each problem color in raw processing or on the tiff.

 

Just so you know where I'm coming from, when I shot film, I carried these and a set of Linhof 70mm glass color correction filters, plus a 3 color meter on all jobs. (The 3 color meter is only useful for measuring continuous spectrum lights - daylight, flash, tungsten.) Also filters to go over my lights. I'll sell these filters cheap now - they originally cost about $10-20 each. $100 takes all. Don't fight over them