White Balance examples

[Mike McCarty]

The following is from the instructions which came with my gray card:

"Light meters and camera meters are calibrated to average the light reflected off a scene so that the <film> will record the scene as average. The average scene will reflect approximately the same as a gray card or 18%. However, if the scene is not average, it is necessary to make an adjustment to the setting of your meter. This is the time to use your gray card. It will help you determine the proper exposure adjustments."

The following is from my D70 instruction book regarding white balance. Procedures will vary from camera to camera:

The color of the light reflected from an object varies with the color of the light source. The human brain is able to adapt to changes in the color of the light source, with the result that white objects appear white whether seen in the shade, direct sunlight, or under incandescent lighting. Unlike the film used in film cameras, digital cameras can mimic this adjustment by processing images according to the color of the light source. This is known as "white balance."

***

Preset white balance is used to compensate for light sources with strong color contrast. A neutral gray [gray card] or white object is placed under lighting that will be used in the final photograph and the white balance is measured by the camera. [my camera will also allow you to use the color balance from an existing stored photo]

I take this to mean that white balance is an extension of exposure. A "next step" that film could not achieve. Where exposure deals with the amount of light, white balance deals with the color, or temperature, of that light.

Some films were better adapted to certain types and temperatures of light than others, and if you didn't do your homework to match your roll of film to the task at hand it just came out wrong. The same could be said for digital except that we can make our adjustments (much more precise adjustments than the range of film choices would offer) per image, not just per roll of film. Not unlike film speed, or ISO.

[Richard Budig]

Thanks for the peek inside your manual.

Getting a gray card isn't tops on my list, but if I run into one, I'll pick it up. I'm having improved results just resetting my white balance for new situations. However, I would like to see what happens with the gray card, too.

As an aside, I'm becoming more and more impressed with these digitals, even my twinky little Konica Minolta. As you said, with the standard old 35 mm camera, if you got the wrong film, or forgot to crank in the correct ASA numbers, or any of the other things that could go wrong, you often has a batch of useless photos to throw in the trash. Now, however, with the more versatile digital cameras, and with something like Photoshop as a back up, some rather nice work can be achieved.

[Mike McCarty]

What I appreciate a lot is the ability to adjust on the fly, from one image to the next. With film you could shoot a roll of 36 and never know for sure. Also, I really like the ability to practice and test without spending a dime.