Jeff
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 p.33 #5 · ['NEW Fix' UPDATE!] - MkIII AF still broken | |
OK, for all you 'detractors', here's a chance to prove me a complete idiot.  FWIW, the only reason I commenced trying to calibrate lenses is that my initial test shots off the back deck were all over the place, focus-wise. As usual, I began to question my skills as a photographer, having used SLRs for 27+ years... 
This morning, using a tripod-mounted camera and focus target, I first shot with all three of my lenses, just to see where each was at. I've spent the last 2+ hours attempting to calibrate one, single prime lens, the 50/1.4. I figured I'd start there, since it was (I thought) 'simpler' than doing a zoom (if it indeed is simpler, I'll give up before I get through the rest of lenses, but that's for me to worry about).
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In the case of the 50/1.4, at "0" adjustment, center-point/no expansion, One-Shot:
- Focused at 4', lens was backfocusing by a variable 6"
- Focused at infinity (~1 mile), the focal plane of the lens was roughly 50-150 feet in front of the camera, with the 'background' (the subject) being somewhat to quite soft.
In trying to correct for the close-in focusing, about a "-3" did the trick, roughly: With the "-3", however, infinity focus was still quite far front-focused.
50/1.4, at "-3" adjustment (for close-focusing):
- Focused at 4', lens was approximately calibrated
- Focused at infinity (~1 mile), the focal plane of the lens was still about 50-150 feet in front of the camera, with the 'background' (the subject) being quite soft.
OK, so that won't work for me, I then proceeded to calibrate to infinity, just to see what happens.
50/1.4, at "+10" adjustment (for infinity-focusing):
- Focused at 4', lens was backfocused only about 2 to 4" (not too bad, I might be able to live with that, or tweak further)
- Focused at 8', lens was backfocused about 10" (not going to work)
- Focused at 15', lens was backfocused >15" (yikes! looked awful)
- Focused at infinity (~1 mile), the focal plane of the lens was about right, with the foreground starting to get a bit soft, as one would expect.
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AAAARRRGH!!!!! Is there a magic setting somewhere that has eluded me? It's like the proverbial "Whack-A-Mole", and I personally can't stand that carnival game!  You'll have to forgive me in advance, but I simply can't stomach providing yet another round of endless screengrabs to illustrate what I'm seeing, you'll simply have to trust me on the qualitative evaluation of the focusing accuracy. Believe me, its pretty obvious to see.
Anyway, what concerns me is that there is (perhaps) a (slight) chance that it may be 'possible' (term used rather loosely) to use an 'All lenses' setting to correct for some amount of consistent camera error (not sure about this yet), followed by then re-calibrating each lens using the 'All lenses' setting to then get a specific setting for each lens. At this rate, that would probably take 10 to 20 hours of messing with, but I honestly can't imagine that it will be successful, based upon what I've seen. And yes, for the record, my AI Servo seems to work rather well, comparatively. Go figure; from the frying pan to the fire, pick your poison.
Has anyone else experienced such results with this? Were you successful in finding the 'magic settings' that cured these One-Shot ills?
So, please feel free to make suggestions to my approach, shoot holes in it, demonstrate to me how it is me, and not the camera. Please, I'm serious, I want it to be me, really! Before you start taking shots at my 50/1.4, it has in the past performed fine on my 1Ds and 30D, though admittedly not as well as my two "L" lenses, the 24-70/2.8L and the 70-200/2.8L IS. I will tell you that even though I haven't yet rigorously tested either of those two lenses, it would appear that they may also behave somewhat randomly, but I want to make sure that my methods are relatively sound before I proceed. 
Thanks for listening, and I'd appreciate any help anyone might be able to provide. Despite any potential appearances to the contrary, I want my camera(s) to work, and will do whatever it takes to ensure that happens, since I'm apparently stuck with the MkIII. The 40D, on the other hand, is still within its return period, and let's just say it remains to be seen, though I guess my next step should be to see if the 50/1.4 behaves the same on it. All my lenses have, in the past, performed adequately on both the 1Ds and 30D, so if my lenses are 'broke', it must be the MkIII that did it to them...
Sigh.
Regards,
Jeff
PS: If this 50/1.4 does need calibrating by Canon (which it may), someone please convince me how spending $150 to calibrate a $280 lens makes sense. 
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