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Jeff Keller
12-05-2004, 09:56 AM
I recently got the Canon EF-S 10 - 22 mm lens for the EOS-20D. While it's a very wide lens, it has tremendous barrel distortion. I've tried correcting it using PanaTools, but I still don't think I'm doing the best I can. I have attached before and after pictures below... if anyone has any suggestions, please do reply! And if this is as good as you can get, also reply!

The attachments are before, then after.

kgosden
12-05-2004, 10:11 PM
Jeff, I think it looks much more like normal perspective distortion rather than barrel. None of the very straight lines in the buildings exhibit any substantial curvature as would be expected from barrel distortion. I had very little trouble using a distortion transform in PS to square things up. I would bet that a lens this wide tends to accentuate the perspective effect; even a slight tilt from vertical causes dramatic changes.After transform (http://www.gosdenfamily.net/~ken/images/IMG_0628_pers.jpg)

Jeff Keller
12-05-2004, 11:08 PM
Jeff, I think it looks much more like normal perspective distortion rather than barrel. None of the very straight lines in the buildings exhibit any substantial curvature as would be expected from barrel distortion. I had very little trouble using a distortion transform in PS to square things up. I would bet that a lens this wide tends to accentuate the perspective effect; even a slight tilt from vertical causes dramatic changes.After transform (http://www.gosdenfamily.net/~ken/images/IMG_0628_pers.jpg)

Hey that's pretty good, Ken. Could you post some step-by-step directions for how you did that?

Thanks,

NeoteriX
12-06-2004, 12:31 AM
http://pdesigner.net/photoshopcs/1_10_3_3.html

Those are actually instructions exactly from photoshop, and are well done. It should be exactly what you're looking for, Jeff.

Jeff Keller
12-06-2004, 10:07 AM
http://pdesigner.net/photoshopcs/1_10_3_3.html

Those are actually instructions exactly from photoshop, and are well done. It should be exactly what you're looking for, Jeff.

Hey, thanks, I'll have to try that out.

kgosden
12-06-2004, 11:57 PM
Jeff, while theabove method should work I have not tried it. Like much of Photoshop there are many routes to a result. I use the Transform function more like this method (http://www.outbackphoto.com/workshop/PSPerspectiveCorrection/PhotoshopPerspectiveCorrection.html) . I generally choose 'distort' over 'perspective' under Transform since it allows for independent control of the various points. It is also sometimes helpful to turn on /View/Show/Grid to make it easier to find vertical and horizontal references.