Thanks Keith and John, for your detailed responses.
Originally Posted by Keith B
5DII, sorry for not mentioning that. I haven't bothered with MA yet. But I believe- especially in the eyeglass shot- we can see the subject pass through the focal plane.
Originally Posted by Keith B
I agree. I'm happy with the sharpness of my lens wide open, but I don't think it is as sharp as yours (though it is hard for me to tell for sure about these things).
Originally Posted by Keith B
I'll use a fancier one next time []
The CA on your lens *seems* like a lot less, but I'm not totally convinced. In those light pics, the background is black, so the lights are *way* overexposed. Yours have a darkish background, true, but perhaps not as dark. In normal pictures, even when I shot at glints of sunlight against dark backgrounds during the day, I get a lot less.
Oh, I don't know.
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Originally Posted by neuroanatomist
I tried with the 85 f/.8 and the results were horrendous. I haven't had a chance with the 85 f/1.2 yet (tonight?), but I doubt very much that I will get usable results. I'll get back to you on that. It would be *awesome* if I could use the 85 at f/1.2 for astrophotos (in fact my joy might just be enough to outweigh my angst at KR being right), but I'm still pretty skeptical. I agree that we're seeing mainly axial CA, not lateral. It's absolutely gone at f/4.
I wasn't aware that axial CA was minimal at infinity. Are you sure about that? I don't know anything, but... if the purple wavelength is just a bit off from the green, I'll get a purple disk, even when green is focused at infinity, won't I? (I'll believe you if you say otherwise)
Thanks for the cool info on CA, by the way.
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