Blurring the AB channels Folks, The use of the AB channels in LAB continues to cause confusion. I have a few questions about some techniques I've read about and tried, but wanted to get some feedback on others experiences. This is said to reduce some of the rainbow artifacts common to digital cameras. This is said to reduce some of the rainbow artifacts common to digital cameras.
Gray noise is always preferable to colored noise.
The A and B channels do not contain contrast information and thus do not affect sharpness. The only drawback of blurring them is that areas of sharp contrast in colors may get a little fuzzy. If you have small colored objects you have to watch out for this problem. The method you describe of blurring the Blue in color mode is also effective. I would think, however, that for all practical purposes the results would be the same.