Introduction to White Balance for Digital Camera Users (Part III): Gray Card or White Card?

In the last week I received many emails asking which is better for measuring white balance accurately via a digital camera, a white card or a gray card, so I'm adding an unexpected Part III to my series on White Balance. (Part I, Part II)

Without knowing it, they've asked a question which has an technical answer, though not one they're expecting, and an unexpected practical answer too.

Let's go back to Part I of the series and review what white balance is:

"White balance is the process of adjusting color casts, so that objects which appear white to human eyes/brains are rendered white in the photograph by the camera."

To put it more simply, photographers set a digital camera's white balance to get the colors in images “right,” where the images' colors are what photographers' brains tell them their eyes are seeing.

Introduction to White Balance for Digital Camera Users (Part II)

Last week, in Part I, I discussed the concept of white balance and defined it. The general idea of white balance is to get objects which appear white to human eyes/brains to be rendered white in your images, so the rest of the colors will render properly as well.

I also discussed the important concept that sometimes, things we consider to be “white” aren't always white when we look at them, and that it's not wrong to ensure they don't look white in our images. During the “golden hours,” for example, white can appear “golden.” At sunset white buildings can take on red and golden hues.

This week I'm going to discuss the practical side of getting your white balance “right,” or at least as “right” as you can get it, so the colors in your saved image are rendered as you saw them.

Introduction to White Balance for Digital Camera Users (Part I)

I'm often asked about white balance by travelers using digital cameras who periodically have a noticeable and sometimes severe color cast on their travel photos. More often than not I'm queried about what white balance actually is, why “auto white balance” doesn't work, and how to get the color rendition of a scene “right.”

It turns out that white balance is a difficult term to define for most people. Here's my try.

White balance is the process of adjusting color casts, so that objects which appear white to human eyes/brains are rendered white in the photograph by the camera.

I'm sure you're asking what the heck that means.

Photography is all about light. If we examine light, which from the sun appears white to our eyes, we find it's made up of a whole spectrum of colors, each with its own color temperature which describes its individual color. Cameras need the ability to render the colors of scenes as the human eye sees them, and that isn't necessarily easy.

It's winter. It's snowing . . . blue?

If you live in the northeastern US, the weather this past weekend ensured you knew it was winter. The snow came down, and some areas got as much as a couple of feet.

Many went out in the last few days to make photographs of snow scenes, only to review the photos and see blue or gray snow.

Unfortunately, digital cameras aren't as good as the combination of our eyes and brains, which are fantastic at color and contrast correction and have a large dynamic range. Whether we see snow in the sun, or shade, or even at night, unless the light illuminating the snow is colored, we see the snow as white.

Cameras don't see the same way we do. They can be fooled by blue skies or shady conditions for snow scenes. The problem is, in snow conditions, the camera often can't set the image's white balance correctly. This is even true with expensive DSLR cameras.