What does white balance do on a camera?

Comments

• bruto

  January 2015 edited January 2015

  White balance does more or less what you would expect it to do, which is to decide (sometimes wrongly) what, of the various things your camera sees, will be rendered as white in the image. Along with this, of course, it also changes the color balance of other shades, centered around the rendition of white. Roughly speaking, for example, if you are shooting indoors under a yellowish incandescent light, and set the white balance to "incandescent," it will render white paper as white even though the light is heavy on yellow. If you go outdoors and leave your setting at "incandescent" the same paper will be rendered as blue because the white balance is set to the wrong light. If you set your white balance to sunny outdoor setting, and shoot indoors, everything will be distinctly yellow. A warmer (yellower) setting will, in moderation, tend to make colors "pop" a little more.
  
  White balance is a tricky thing to get exactly right, not only because light varies so much, but because even different lenses transmit it differently. The D3200 set to automatic balance with its kit lens will produce a rather cold, bluish light outdoors, though it does pretty well indoors. If you find your outdoor shots are too blue, try setting the white balance to "cloudy."
  
  If you are not shooting in RAW mode, you should start now. You can then open any picture in View NX2 or many other programs that read raw files and adjust the white balance without altering anything else, and can revert to the original without loss. You can do this quite precisely, and set your white balance to a specific color temperature.
  
  You can also preset a manual white balance, in the menu, as well as altering any of the presets if you don't find them quite suitable.
  
  I have not experimented with jewelry but I am not entirely sure that a pure white background will do better for you than a colored one. You may need to experiment a little with backgrounds, but I would recommend working largely to get the color balance of the jewelry itself right, and then experiment with different shades of background. Remember too that "white" itself is pretty vague. What appears white depends on many factors, including what surrounds it, and the eye's ability to compensate for error is far greater than the camera's. The decision by the paper maker is one of white balance too, deciding on what will look white to you when you pick the paper up. There's no real absolute here.
  
  I am guessing here that you will never have uniformly satisfactory results (or at least not without lots of work) unless you set up a consistent artificial lighting arrangement for your work. Most product photography is done with a repeatable light source. Once that light is set, the camera's white balance can be adjusted to taste. Once you have a known source of light, you can set a custom white balance, and it will look right each time.