Setting the Image's Individual Channel Mid Tones—Color Cast Correction
Setting the individual channels' mid tones corrects any remaining color cast in the image without changing the previously set white point, black point, mid tone point, and 1/4 & 3/4 tone points to any extent. This is important because we do not want to undo the good we have done. This adjustment is made 'by the numbers." We will use the Color Sampler tool to set sample points in neutral mid-tones in the image for color evaluation. The individual channel mid tones setting is critical to the final color correction of the image. The mid tone setting is performed in the Normal mode to since it is a true color correction step.
Info Palette
Make sure the Info Palette is visible on your screen. If it is not visible, select .
Color Sampler Tool
The Color Sampler Tool is nested with the Eyedropper Tool in Photoshop's tool Palette.The Color Sampler Tool allows you to select up to four sample points in the image. We will locate four near-neutral tones close to mid value. Remember that there are very few true neutral tones. Using four sample points in conjunction with the Info Palette we can look for a pattern to emerge in the color shift of the image. For example, if the Red channel value is higher than the other two channels in three of the four readouts, we can assume that we need to lower the Red value to the level of the other two channels.
