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08-20-2013, 07:21 AM   #1
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Micro focus How to ?

I am trying to find information on how to make micro focus adjustments on my K7 & K5 for a couple of different Sigma zooms. Please Help ? I'm an old fart and have a tough time at first walking through these issues or being able to find the right info, steps to walk through. Usually after I have done it once or twice I'm good to go. Thanks in advance for your help.


Last edited by marquis1955; 08-20-2013 at 07:25 AM. Reason: poor wording
08-20-2013, 07:52 AM   #2
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For the k-5 read page 126 of the manual for the basics.

A few points to keep in mind:
  • Individual lens AF fine tuning is only available if the lens identifies itself to the camera. Sigma in particular has problems with this, as sometimes different lenses identify themselves as the same lens. Manual lenses with no ID chip cannot use individual AF fine tuning but can be adjusted using the global camera adjustment.
  • AF fine tuning depends on a precise, accurate, repeatable testing. If you cannot do that you are more likely to make things worse. Quite often the margin of error in the test performed is larger than the actual AF error thus making AF fine tuning no more than a lucky guess.
  • A proper test requires a good target, set up on a tripod with precise alignment to the plane of the target in both horizontal and vertical axis.
  • A proper test is repeatable, use 5 - 10 trials and average the results, throw out any outliers.


Here is an article that might help with more detail: Fixing Front and Back Focus - Introduction - PentaxForums.com
08-20-2013, 09:17 AM   #3
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Hey there, welcome. I just wrote a reply to a similar thread, and it might be relevant. The K-7, K-5 and K-30 are not exactly the same, but the AF adjust should be very similar.
Here is that thread, it contains links to AF charts. Hope it helps
08-20-2013, 10:12 AM   #4
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Thanks Much ! I appreciate the help

08-20-2013, 10:12 AM   #5
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Thank you Jatrax
08-20-2013, 12:16 PM   #6
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QuoteOriginally posted by jatrax Quote
For the k-5 read page 126 of the manual for the basics.Individual lens AF fine tuning is only available if the lens identifies itself to the camera. Sigma in particular has problems with this, as sometimes different lenses identify themselves as the same lens. Manual lenses with no ID chip cannot use individual AF fine tuning but can be adjusted using the global camera adjustment....
Good info, thanks Jatrax. But how do I know if the K-5 recognizes my third-party lens (Tamron)? I am able to set and then "Save" my settings in "AF Fine Adjustment."
.
08-20-2013, 05:23 PM - 1 Like   #7
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QuoteOriginally posted by *Rich Quote
But how do I know if the K-5 recognizes my third-party lens (Tamron)?
AFAIK, if the lens is listed in your EXIF then the camera recognizes it. Maybe recognize is not the proper word, how about 'distinguish between'. The problem with some of the Sigma lenses is they appear to use the same ID, or at least the camera thinks they do, so you can have two widely different lenses but as far as AF fine tuning the camera thinks they are the same lens.

To test, shoot an image with your Tamron and check in Lightroom or whatever software you use, if it says the lens is a "Tamron (your model #)" then you should be fine. If it says "Tamron Lens" or "A series lens" then you may have an issue. But I believe this is only a problem if you have more than one lens that the camera can get confused. FI, if you have two Tamron lenses and they both list out in the EXIF as "Tamron Lens" then the camera cannot tell which is which. If one lists as "Tamron 17-50" and the other lists as "Tamron 24-70" (or whatever) then you should be fine.

Note this has nothing to do with taking pictures, just the AF fine tuning as the camera keeps individual settings for (I think) 20 lenses.

Hope that makes sense...
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