White Balance examples

[Allan Rahbek]

Originally Posted by Mike McCarty

I've not figured out how to use the card for taking sunset pictures. When the light source is your subject where do you place the card?

Mike,
I don

[Richard Budig]

Mike, et al:

What else can you tell me about the white level or white balance in these digitals.

I'll go first: I recently discovered my white balance settings, and so far, I'm happy as a clam in fresh ocean water. I have been getting better quality photos and color since learning about this through the manual that came with the camera (Konica Minolta Dimage Z10).

However, I've been reading your comments about the gray card. Are you using this in place of the plain white paper mentioned in my instructions, and if so, how is it working. If not, what benefits can be gotten from using a gray card? Do you use it in the same way as the plain piece of white paper?

[Mike McCarty]

Richard,

I believe that it is in place of the white paper. My understanding is that the 18% gray card is the precise "benchmark" from which the camera can measure reflected light.

I don't have any experience with using the white paper method. I would think that one trouble would be that there are all sorts of whites.

My camera does a pretty good job with auto wb if I'm moving around a lot and the card is not practical, but if the scene remains constant I would rather make a quick gray card measurement.

That pretty much exhausts my knowing ...

[Allan Rahbek]

Originally Posted by Mike McCarty

Richard,


I don't have any experience with using the white paper method. I would think that one trouble would be that there are all sorts of whites.

...

I have to admit that I don

[Richard Budig]

Mike, et al:

You have driven me back to my manual, which, I see upon closer inspection, gives me three options for white balance.

First is automatic. It does if for you.

Second is Preset White Balance, which allows me to select daylight, cloudy, tungsten, flourescent, and flash.

Third is Custom White Balance, where the piece of white paper comes in. And, I've had one of those "DUH" moments in thinking about this . . . I suppose they call it "white balance" since they instruct me to use a piece of white paper.

Basically, I select the Custom feature, hold the lens about six inches away from the white paper, which is illuminated by whatever light I intend to use, press a button to let the camera read the light coming from the paper, and after a moment or two, it automatically finishes up, and my white balance is set for that shoot.

As I said, I've been getting better color and general photo quality using this feature. Of course, I use it for inside shooting. Out of doors, I set it on automatic, and seem to get acceptable stuff.

But Mike's mention of the 18% gray card got me to thinking. I'd still like to hear from anyone who can add to this discussion.

[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.