In a message dated 11/10/2007 5:46:44 A.M. Pacific Standard Time, [EMAIL PROTECTED] writes: In general, barrel distortion gives you a barrel shape, much like parenthesis facing each other. Perspective distortion gives you a pyramid shape. The outer verticals lean in. Perspective distortion is easy to correct in PhotoShop using Edit/Transform/Perspective. After correction, you have to crop, and you'll lose a bit of the frame. Frequently, I apply just a small amount of correction. You don't want perfectly aligned verticals for most shots.
Barrel distortion can be corrected as well, but it's more difficult and usually not necessary. In PhotoShop Edit/Transform/Distort can help some, but there are third party lens correction tools that do a better job. However, I don't find that any of my lenses, including the 16-45 and 12-24, produce severe enough barrel distortion to require correction for normal use. I only remember using such a tool once. It was for a 12mm shot that included a vertical right near the edge of frame. A tiny bit of barrel distortion was visible after the perspective had been corrected. Rob told me how to fix it, and I did, but I don't remember the specific tool I used. Paul =============== Thanks, Paul. I can't think of any time I have really noticed barrel distortion in my shots, including the 16-45 So it's probably not a biggie. Though I may be looking a bit for it now. Marnie aka Doe :-) --------------------------------------------- Warning: I am now filtering my email, so you may be censored. ************************************** See what's new at http://www.aol.com -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
