Got this Datacolor SpyderCHECKR chart from YL Camera today Using it mainly for white balancing purposes, not for camera profiling, since that feature only works in Lightroom and I don't use it. Some test shots:
Well the chart has 3 diffferent sides, and one of them is a big honkin' grey target. However, the grey patches at the bottom row of this chart works for close distances, and lets you see how your camera renders the rest of the colors. Side note, it appears that my old method (calibrate off the white side of my ExpoDisc, has given me warmer results -- 5400K vs 5100K), now this test confirms my ExpoDisc is indeed warmer (even though I bought the neutral one, not the warm portrait version).
The color patches are properly calibrated to very specific colors with minimal deviation. Some software like Adobe Lightroom recognizes the color patches, and can be used to profile your camera's color response so that you get matching color reproduction. Without auto-profiling, one can still use the color chart for white balancing (via the grey patches), and then if needed manually hand tune colors.
