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|| SportsShooter.com: Member Message Board
Canon 85mm f/1.2 L II lens and Chromatic Aberration
Brian Tietz, Photographer
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Fort Myers | FL | USA | Posted: 3:49 PM on 11.22.09 |
->> I have had my 85 for a couple years and love it for portraits, but have always noticed a little CA in highly reflective objects or when I blow out the background behind a subject sometimes I'll find it creeping in on the tips of hair. I rarely shoot lower than f/1.8 but I'm starting to notice it a lot more lately and not sure if it is because I have been using it a lot more or not,but it is starting to get really annoying. I remember my 35mm f/1.4 L doing the same thing on occasion. Any one else have this problem, is this just the way it is with this lens or do I need to send it in for a tune-up? I have been checking out the Zeiss glass as a possible alternative any one using those with any luck
Here are a few 100% crops of what I'm talking about.
http://www.sportsshooter.com/btietz/85ca/index.html |
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David Harpe, Photographer
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Louisville | KY | USA | Posted: 3:55 PM on 11.22.09 |
->> Have you switched from a crop body to a FF body? That would make a difference.
I know it's always best to get it right in-camera, but if you want to fix it in post I highly recommend the "PTLens" application and plug-in from epaperpress:
http://epaperpress.com/ptlens/
An amazing tool for correcting CA and lens distortion. I find the results are much better than the equivalent tools in Photoshop/ACR. PTLens has a built-in database of geometric distortion correction parameters for specific lenses. CA is easily tweaked using manual settings. A great tool.
Dave |
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Brian Tietz, Photographer
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Fort Myers | FL | USA | Posted: 4:05 PM on 11.22.09 |
->> I'm using it on both a full frame 1Ds MkII and a 7D, not to make you get all scientific but why would the crop body make the CA worse?
Thanks for the Link I'll check it out!
-b |
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Robert Catto, Photographer
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Wellington | NZ | New Zealand | Posted: 4:14 PM on 11.22.09 |
->> I think David was suggesting that the FF body would make the CA seem worse - ie. it would be worst towards the edges of the lens, which you wouldn't have seen on a crop body.
Aside from that, all I can add is 'yep, it does that'. My 24L & 85L are very much the same, but a lot can be fixed with the Adobe Camera Raw Lens Correction tools; I haven't tried PTLens myself for that.
R |
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David Harpe, Photographer
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Louisville | KY | USA | Posted: 9:42 PM on 11.22.09 |
| ->> Yeah...what Robert said. If you have a FF body, you're seeing the edges of the lens elements...which is where CA is most pronounced. Towards the center you are in the sweet spot of the lens. Shoot some white wall/black letter tests with both bodies to see it for yourself... |
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Brian Tietz, Photographer
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Fort Myers | FL | USA | Posted: 10:11 PM on 11.22.09 |
| ->> Thanks guys, that makes sense, the ones I posted were all taken with a 7d and actually fairly close to the center of the frame. Its still a great lens, just wanted to make sure I wasn't the only one with that problem. |
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