Lily Galib, Production Associate, Image Quality Control, has written a three-part post on the ins-and-outs of light value adjustments. Part 1 covered histograms, part 2 working with Photoshop’s Levels Adjustment Tool and the Curves Adjustment Tool, and part 3 concludes with color.
Color:
Levels and Curves adjustment layers showing the color channel selector. This is where you can select individual color channels to work with if you’re making color adjustments, or RGB if you’re adjusting light values.
When making color adjustments with the Levels Adjustment Tool and the Curves Adjustment Tool, the basic functions are the same (3 set adjustment points for Levels; anchor points for Curves) but you break the histogram down into the individual color channels. There are a few different color working spaces, but the ones you will most commonly encounter are RGB and CMYK. Generally speaking, RGB is used for images that will be viewed on a screen and CMYK is used for print. Digital cameras capture images in RGB, which stands for red, green, and blue. CMYK stands for cyan, magenta, yellow, and black, which are the ink colors used in printing. I’m only going to deal with RGB here since it is the color space you’re most likely to use. At ARTstor we always work in RGB. (more…)
