Slide Away The Aberrations
If you see areas of bright-colored fringe appearing around objects in your RAW photos, you’re suffering from Chromatic Aberrations (well, you’re not, but your camera’s lens is). Under the Lens tab in Camera Raw, there are two sliders (Fix Red/Cyan Fringe and Fix Blue/Yellow Fringe) that you let you slide those problems away, but seeing the problem clearly enough to eliminate the fringe is your first challenge. That’s why you’ll want to know this tip: If you hold the Option key (PC: Alt key) while you’re dragging either Chromatic Aberration slider, it will only show the two channels you’re adjusting in the preview area, making it easier to see—and repair—the problem.
This is a superb hint – it truly does make it so much easier to correct CA.
Many thanks – Rod