4. Expose for the white card. Make sure your white card is around 50-60% brightness. Any brighter than that, and you’ll get inconsistent results or the camera might just say something like "Overexposure Error."
5. Run a white balance, as in hit the white balance button or switch on the camera, and you should see a result. To check for accurate results, an RGB waveform can show you what’s really going on. If things still seem off, then run the white balance again and see if the results change.
An auto white balance can be essential when working with commercial lighting and also in multi-camera environments. However, a common complaint about the results of a white balance like this is that things can end up looking green or magenta.
WHY SO GREEN?
Running an auto white balance on a camera always adjusts the levels of the red and blue components of your image. Some cameras, however, will also adjust the green level of the image (or rather, the red and blue levels relative to the green). Red and blue adjustments make sense when thinking of traditional lighting and daylight. However, with new lighting technologies, having a green level adjustment is also essential. So on some cameras, you can run a white balance over and over, and the green levels seem off. A white balance that has too much green will certainly make the image feel a bit green overall, and too little will cause the image to go magenta. That’s why cameras like the Sony FS700, Sony F5/F55 and ARRI ALEXA all have incorporated a green/magenta level adjustment option. This adjustment is relatively small but can make a huge difference in the resulting image.
WHITE WITH YOU
White balance may not be the most glamorous subject, but it’s a big part of production these days. If you’re shooting with a camera that records raw data, you might think that white balance isn’t important. However, on set is the best time to determine proper balance, and that data will make it to post through metadata, which can really speed up the post process. So keep those whites white, especially if you’re shooting a Clorox commercial.