October 23, 2014, 11:32:53 AM

Author Topic: AFMA values beyond -20  (Read 451 times)

Gert Arijs

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AFMA values beyond -20
« on: March 07, 2014, 10:04:10 AM »
Hi,
I have bought a used 5D3 last month and recently the Tamron 24-70 f/2,8 VC (also used). I just did AFMA for this lens (as I did with my other lenses before) and even with the value set to -20, it's just not enough. It should be about -22 for Wide and about -26 for Tele (these are educated guesses). What can I do?
Notes:
-I performed a more or less "real life" test at f/4 and it's perfectly ok. Same test at f/2,8 and it seems quite ok.
-I do the following to determine the AFMA values: Tripod, detailed flat object (ie newspaper), camera and object aligned. I defocus manually, and autofocus; then I check the focus using liveview and adjust manually when necessary; I repeat this about 3 times using the middle focus point first and another 3 times for two outer focus points (both left and right). I always defocus first.
-I got very consistent results with my other lenses on this and previous bodies. So I'm confident I do not need FoCal or other packages. It's just this Tamron, which seems too off for calibration but turns out to be ok in real life...
Suggestions?
« Last Edit: March 07, 2014, 10:09:07 AM by Gert Arijs »
5D3, 7D and old 1Ds3. Gitzo with Markins.
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AFMA values beyond -20
« on: March 07, 2014, 10:04:10 AM »

neuroanatomist

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Re: AFMA values beyond -20
« Reply #1 on: March 07, 2014, 10:09:29 AM »
All you can really do is send the lens, body, or both into their respective manufacturers for adjustment.
EOS 1D X, EOS M, and lots of lenses
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wickidwombat

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Re: AFMA values beyond -20
« Reply #2 on: March 09, 2014, 01:16:30 AM »
yep send it in for recalibration then it should come back good
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Re: AFMA values beyond -20
« Reply #2 on: March 09, 2014, 01:16:30 AM »