16th February 2005, 03:03 PM
Newbie question: White Balance.
Hi to all,
from what i know, white balance is suppose to find a reference point which represents white and then calculate all the other colors based on this white point.
Are we suppose to use white as reference even the environment is yellowish in color?
16th February 2005, 04:31 PM
The purpose of adjusting white balance is actually to achieve a scene that is close to what the eyes see originally. The human eye is amazing adaptive to different lighting conditions, and with the wide dynamic range our eyes are capable of, we tend to see white objects as their original white or close to it while ignoring the effects of environmental lighting.
The simple way of correcting white balance is simply to find a spot in your picture that you KNOW is white or near white. For example, a white sheet of paper, cloth or a white wall. Then by setting it as the absolute white point, the levels of the picture can then be recalibrated according to this point.
If you can actually find a white spot in your picture which is not affected by the environment lighting at all... then there usually isn't a need to correct the white balance any more.
However, there's often a danger of over-correcting especially when you are in situation with strong cast lightings. For example, at concerts or performances, where the spotlights are usually halogen or tungsten light with an orangy/yellow cast. In these case, no matter how good your eyes are, you will still be able to see the colour cast on white spots. If you try to set white point on these white spots, you will most likely find that your picture will turn out overly bluish. (Though you can achieve a balance). Correctly the white balance sometimes tends to take out the ambient atmosphere of the pictures, which some photographers will prefer.