Why does color cast matter?

Color cast is everywhere. Take a photo of a snowscape on a sunny day. The snow is blue, not white because it reflects the color of the sky. So this color cast is OK. What about the bride in the sparkly white dress on a beautiful grass lawn? Is green the color she wants in her gown? On her skin?

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White balance

A white balance setting that doesn’t match the light in the scene is an extreme example of colorcast. Consider a sunny scene with the white balance set to tungsten or incandescent. It’s way too blue. The same goes for a daylight WB setting inside. The result is a very yellow colorcast.

For the most part, the white balance settings in our cameras get us fairly good results. A day with bright sun shining through thin clouds looks OK with a daylight balance. The true color the camera sees is bluer than daylight, but not by much. Certainly, it’s not enough difference to see with our eyes.

How we see color

Our brains know what white looks like. When we view a scene, our mind does an auto white balance based on white objects we see. Our vision does this without conscious thought. This 20-second video shows how we adjust for color change. At some point, the light on the coffee cup will become warmer in 100ºKelvin steps. When do you see the cup becoming yellow?

Taming color cast

Drastic changes in color are easy to see when a photo with the correct color is available. Move the slider on the photo below to see the difference between the correct color balance, daylight white balance on the camera with 5500ºK light and the 3000ºK light that appears at the end of the video. It’s a big change.

The best way to tame color cast is to use a color reference that has absolutely neutral patches like the ColorChecker Passport Photo 2. Clicking one of the gray patches with the White Balance tool in Lightroom immediately makes the color neutral.

Tools used for the color temperature video

• Canon 1DX Mark II
• Sigma 25-105mm f/4.0 DG OS HSM Art lens
• Really Right Stuff 3 series tripod
• Really Right Stuff BH-55 ball head
• X-Rite ColorChecker Passport Photo 2
• Illuminati IM-150 light and color meter
• Luxli Cello RGBAW LED lights (2)

Color is a matter of taste

The opening photo is daylight color balanced. The snow and ice floes in Turnagain Arm outside of Anchorage are blue because they are lit by the super blue sky. The photo below has the blue color cast removed. Technically, it is a more accurate version. Aesthetically? That’s a creative decision.

Photography except where noted: ©Kevin Ames