I've been waiting for Capture One to come out with support for the 20D. And waiting. And waiting.
Finally, I got fed up trying to use PS CS's Raw Converter - I say "trying" because I was really running rather blind. So I went out and bought Bruce Fraser's "Real World Camera RAW with Adobe Photoshop CS" to learn the program correctly. It kinda hurt to pay $35 for such a small book. It hurt more when I found only that only half the book talks about RAW while the rest covers the File Browser which is useless to me.
It's worth the $35, really. And there is a section on Workflow that I haven't read so it's not *all* File browser.
And I'm not yet convinced that I'll convert to PS CS for RAW conversion, but I did learn one neat trick, and that's how to correct for Chromatic Aberration (CA from here on in).
I picked an image of a mountain scene reflected in a lake with some trees and a rotten little branch that stuck into the corner of the image. (Check the *entire* viewfinder!) The mountain had a background of mostly blue sky with some clouds, and the sun was directly behind me. After processing and final sharpening I ended up with this:
Well that halo around the mountain is pretty darn ugly, and I deleted it and went back to the original to find the problem. Zoomed in at 100% I found the CA.
Here's a couple of 100% crops from the original:
At 100% the branches showed some enormous CA, which really isn't surprising given that situation. If you shoot something thin like branches in shadow against a bright sky you should expect some CA. The mountain shows a definite halo along the left edge. Yuck.
Again, this shouldn't have been a surprise given the lighting. And to top it off I was using a zoom, so this made for even more CA. The lens, the Canon 17-40 L, is a great lens but I think any lens will show CA in the picture.
So I deleted everything and went back even further, back to the RAW opened in PS. I zoomed to 200% and went into the corner with the branches. I then flipped to the Lens tab. (If you don't see the Lens tab then click on Advanced up near the OK & Cancel buttons.)
Yuck. Gotta fix that CA.
I grabbed the "Chromatic Aberration B/Y" slider and started moving it around. Wrong. It just made the CA more green and purple when I slid it to the left and more yellow and blue when I slid it to the right. So I put that back to 0 and grabbed the "CA R/C" slider and moved that one around. Much better.
Sliding to the right made the CA more cyan and red. Sliding it to the left, not too much, seemed to help. Then I held down the Alt key when sliding, and I could see things better. Holding the Alt key hides the other channels and makes the process clearer because of this.
Nudging back and forth just a little showed me that setting "CA R/C" to -33 looked about as good as it was going to get. Then I went back to the "CA B/Y" and played with that a bit, and found that +5 made it just a little better. It looks much better, as you can see in these 100% crops.
The branches are much better, but still look a little funky, but remember the lighting here. They are *not* going to look perfect. But check out the edge of that mountain - no halo!
Woo-Hoo!
So I finished resizing, processing, and sharpening. It looks a bit better, huh? The halo around the mountain isn't so apparent any more. Yes, it's still got a halo because it was sharpened, but it's hardly as bad as before. The obnoxious branches in the corner definitely look sharper, as do the tops of the trees.
Before:
PS CS's CA correction is pretty cool. I'm happy.
