Don’t Use Crop To Fix Barrel Distortion
Problem: You're trying to fix barrel distortion that appears on a photo you're editing, but using the Crop tool's Perspective feature is a guessing game. You try the crop and it doesn't look right; you have to undo it, and guess again. Solution: Don't use the Crop tool's Perspective feature (found in the Options Bar), even though it was specifically designed to address barrel distortion. Use the standard Free Transform command instead by pressing Command-T (PC: Control-T) and then pressing-and-holding the Command (PC: Control) key while you drag the corner handles to create your perspective. Doing this gives you a live onscreen preview as you work, so fixing the distortion takes just a few secondsâ”unlike Crop's Perspective.
Very nice tip. I’ve used the Crop Tool’s perspective option a few times, and it never really looked quite right to me. Thanks for the tip Corey!
Blake
There is also a CS3/CS4 filter called “Lens Correction” under the Distort menu.
CS3
http://livedocs.adobe.com/en_US/Photoshop/10.0/help.html?content=WSF65FB40F-00F5-445a-BD9A-38B3737A9A19.html
CS4
http://help.adobe.com/en_US/Photoshop/11.0/WSF65FB40F-00F5-445a-BD9A-38B3737A9A19a.html