White balance is the cornerstone of color management. Although most modern digital cameras have excellent auto white balance nothing compares to customizing your camera’s white balance manually.
Before demystifying the process of white balancing your camera manually it is important to understand the fundamentals of what white balancing is and its importance in creating superlative images. White balancing was first introduced to us when video cameras replaced movie (film) cameras . Since vidicon tubes and eventually the CCD and CMOS chips are electronic and needed a reference point for color. The positive color primary colors are Red, Green and Blue, when equal amounts are combined (see RGB Spectrum diagram) they create white. Negative primary colors are Cyan, Magenta and Yellow, which when combined make black (CMYK). With digital cameras capturing RGB file information you can see why white is the reference point that is used to adjust and render specific colors – particularly neutral colors – correctly; hence, the general method is sometimes called gray balance, neutral balance, or white balance. Color balance changes the overall mixture of all colors in an image.
Before digital cameras were introduced, first to video and then still images, we used emulsion based films not sensors to capture images. The issue is there are only two types of film, positive and negative. Yes, photography is algebraically based! Both produced first in black and white and then color. Most people are unaware, but positive color film (E6 processed slide film) goes through two development stages; and although it was color film, after the first developement is completed the film looks like a black and white negative.
Unlike most of today’s cameras that are programed to do the thinking for you, photographers used to rely on film type for for light sensitivity (ISO/ASA) and color management that was far more complex than today as your choice was film balanced for either daylight (5500 degrees kelvin) or tungsten light (3200 degrees Kelvin). What this means is if the film you were exposing didn’t match the type of light you were using you would have to correct the color with the use of a filter over your lightsource or for your lens. For instance, when you use daylight film in a room that has florescent lights you would use eith a purple FL-W (used for converting white florescent lighting) or FL-D florescent conversion filter. Not only does this try to correct the nasty green cast of florescent lights, but more often it can be used to turn an otherwise gray sunset an exciting violet. If you were shooting tungsten film with florescent light you would use an FL-B filter.
So, how do you white balance? Obviously in today’s world we can correct color temperature quite easily with the proper image editing software, and with the use of a Promaster White Balance Lens Cap Filter. Like anyother white balancing filter it is much easier to use than you would think. Simply place the filter on your lens in place of the lens cap and aim the camera to the area you are going to be photographing and fire the shutter. Then select your camera’s setting to Custom White Balance and select the image you created with the filter and click ok. Remove the lens cap and begin exposing images with great color balance!