Color Temperature & Digital Cameras

by

William Lulow

Way back in the days of film, there were really two basic types of color film: Daylight and Tungsten. You could change one to the other by the use of special filters, if you didn’t have both, but that was about it. Tungsten film was balanced for use with indoor type lighting and Daylight film was balanced for use outdoors. Without getting too much into the science of color temperature, suffice it to say that it is measured in “degrees Kelvin.” This “standard” was named after Lord Kelvin (William Thomson), a British mathematician who lived from 1824 to 1907. He believed in being able to measure things. The Kelvin scale measures the relative coolness or warmth of various light sources. For instance, a match flame registers about 1,700 degrees Kelvin or 1700K. An ordinary table light bulb registers approximately 3200K, a fluorescent light about 3000K and daylight, about 5,500K. The higher the degrees Kelvin, the cooler or bluer the light. The lower the number, the warmer or yellower the light.

Ordinary daylight on a cloudless day registers about the same color temperature as that emitted by an electronic flash unit. This image was made on tungsten film but cross-processed in a developer made for daylight images, hence the bluish cast:

BlueMan(xproc)

Today’s DSLRs are capable of setting a “White Balance” for each exposure that automatically measures the degrees Kelvin of a scene and adjusts the exposure accordingly. There could be times when you might want to set the white balance manually. You have the ability to do that by adjusting the color temperature dial in the camera. If you are shooting at sunset for instance, and you want an interior to have a “warm” feel to it, you would set the white balance to 3200K. This would register the lights of a house normally, while giving the outdoors a bluish cast. This makes for an “inviting” looking image due to the warmth of the interior light. Here is an example:

Aura_0520(Dusk)WEB

The use of the white balance control in your DSLR can be a source of interesting images.

┬áThere are a number of other color temperature settings in most DSLRs these days. They come under the heading of “Picture Style.” Each “style” has a setting you can change manually to yield various different color tones to your images. Some are preset for you, so you might want to check them out through experimentation. For my Canon cameras, they are:

  1. Standard
  2. Portrait
  3. Landscape
  4. Neutral
  5. Faithful
  6. Monochrome

Each has a slightly different color cast (temperature) and you can change the

  1. Sharpness
  2. Contrast
  3. Saturation
  4. Colortone

to give you various tones that you may like.

Monochrome mode, of course, is for shooting in original B&W (which I have written about in another blog article). These constitute quite a number of different settings. Did I say that digital photography was easier? It may be easier to take a decent picture, but the number of settings you can use has increased dramatically. So, make sure you read your manual and by all means experiment.