Jeff
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 ['NEW Fix' UPDATE!] - MkIII AF still broken | |
IMHO it's quite clear from RG's images provided today that the camera still suffers some sort of inherent design flaw in the system, obviously affecting more than just the sub-mirror assembly. There are two things I found particularly disturbing about RG's report:
1) The little ditty about setting AF Microadjustment to -1 fixing some of the issues, and all the caveats thrown in. If you haven't read that part, you need to see it, it's really a rather odd response from Canon as to how the function should be used, and not used.
2) And, more importantly, I must point out a very interesting phenomenon in the 'fast runner ' series, something I've occasionally noticed about my MkIII's soft images. The examples show it very clearly and consistently, and I've not heard RG or anyone else comment on it with respect to actual example images. I've provided a screengrab at the bottom of the post to clearly show what I'm talking about.
[In regard to RG's 'fast runner', I would agree that about 50% is closer to the mark for the MkIII in the 'fast' running sequence (the MkIIn did indeed perform significantly better). For some reason the hurdle sequence was better, perhaps illustrating the somewhat random nature of the beast, although the subject in that one was wearing a white shirt.]
Note in the screen grab below that virtually every time the MkIII has an out-of-focus image, it almost ALWAYS exhibits some sort of secondary 'ghost' image, suggestive of some sort of movement (which at 1/8000th, I'd think is unlikely on RG's part). This is very clearly and consistently exhibited on the 'Brooks' logo the runner's blue shirt, since it has a high-contrast area (dark background with white lettering). With the camera in the vertical orientation, the 'Brooks' logo has a ghosted image above it, indicating some sort of movement somewhere in the system (side-to-side in relation to a landscape orientation). This would obviously contribute to an image's overall softness regardless of the actual focal plane, though it appears to me to be consistenly manifested mostly when the camera ALSO has focused either slightly in front of (or more typically) slightly behind the subject. Note that the MkIIn's OOF images do not exhibit this odd characteristic (at least that I could find), suggesting the lens has nothing to do with it.
Whether the cause of this apparent 'movement' in the system is also causing the focus errors becomes the question in my mind (there is also a chicken-and-egg component here). I suppose there is always the slight chance that it could be lens/IS related, but I would doubt that he was using IS for such sequences, and one would expect it would have been duplicated in the MkIIn images. I have no idea what component in the system could be moving, whether it is a result of the new anti-dust mechanism, due to the sensor moving (which seems unlikely), or some sort of overall 'looseness' in the parts of the camera that is exacerbated by the MkIII's extremely fast shooting rate.
Like I said, I have noticed these 'ghosted' secondary images in several of my OOF MkIII images, and as you all have probably seen, there is a fair amount of internet chatter about overall image softness (not the all-over OOF 'misses' that we've seen so much of), though image softness can often be attributable to user error of a variety of sorts.
====> I would suggest that any of you interested take a close look into this series of images and see if you agree with what I'm seeing. It's quite obvious once you start really looking at the images at 100%.
[ As an aside, I'm currently using the Trial version of CS3, and Bridge3 makes it really, really easy to quickly evaluate these images, especially with the 100% loupe feature (a la Aperture). Nice! ]
I love this camera, the files from it are exceptional, but I bought it to shoot outdoor sports (in addition to serving the purpose that my 1Ds served, which it admirably can). This issue clearly has not been resolved, and it's writing on the wall for the 1DsMkIII (which is, I'm certain, why Rob took so long to make certain of his results). It's also clear by reading in between the lines that it affects every single MkIII produced prior to October 2007, despite the fact that some people have not seen any AF inconsistencies in their specific usage(s). For example, notice that they are no longer talking about 'adjustment', but 'replacement'.
Anyway, more food for thought. Mine will be getting the submirror fix, but to what end remains unclear for my shooting.
Regards,
Jeff
PS: I'd be very curious to hear others' thoughts on a potential reason for the results noted in the screengrab below. I'm getting tired of talking about this too, but RG's tests are significant points of data in this ongoing puzzle, and today's installment provides a compelling illustration of the camera's ongoing AF quirks.
Edited by Jeff on Dec 10, 2007 at 07:11 PM GMT (Reason: Moved wide image below to re-wrap text properly)
Edited by Jeff on Jan 03, 2008 at 02:37 PM GMT (Reason: Title change for update)
Edited by Fred Miranda on Jan 07, 2008 at 03:23 PM GMT
Edited by Jeff on Jan 23, 2008 at 03:55 PM GMT (Reason: Title change for final update)
Edited by Jeff on Jan 26, 2008 at 12:37 PM GMT (Reason: yet another title update to reflect current status)
Edited by Jeff on Feb 16, 2008 at 10:18 AM GMT (Reason: alas, another title change for clarity!)
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['NEW Fix' UPDATE!] - MkIII AF still broken
