# Need to send my Canon 24-105 f/4 L to Canon to be calibrated.



## pulseimages (May 19, 2014)

I just joined CPS Gold and I need to send in my Canon 24-105 f/4 L to Canon to be calibrated because I just haven't been able to get a truly sharp image from it. I know that some people say that this lens isn't the sharpest of the L lenses but others have said theirs is tack sharp.

I've decided to send my Canon 6D with it as well. Should I remove my B+W MRC UV Filter and memory card before I ship my equipment to Canon? Thanks in advance!


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## neuroanatomist (May 19, 2014)

Remove filter, card, battery, strap, etc.


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## verysimplejason (May 19, 2014)

Neuro had said everything. I just wish you luck. Mine is tack sharp since I bought it. If you don't mind me asking, when did you bought your lens?


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## gjones5252 (May 19, 2014)

I thought mine wasn't that sharp but then I bought the ultimate 24-70mm 2.8 ii and saw really how sharp and house close in quality it was. I even bought 3 of the 24-70 thinking I got a bad bunch. They all were similarly sharper and better looking than my 24-105 but not enough I wanted to justify keeping them.


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## pulseimages (May 20, 2014)

verysimplejason said:


> Neuro had said everything. I just wish you luck. Mine is tack sharp since I bought it. If you don't mind me asking, when did you bought your lens?



I bought it in December 2013.


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## dgatwood (May 20, 2014)

pulseimages said:


> verysimplejason said:
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> > Neuro had said everything. I just wish you luck. Mine is tack sharp since I bought it. If you don't mind me asking, when did you bought your lens?
> ...



The more interesting question is when does the date code say it was built?


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## pulseimages (May 20, 2014)

dgatwood said:


> pulseimages said:
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Where on the lens do I find the date code?


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## privatebydesign (May 20, 2014)

pulseimages said:


> dgatwood said:
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http://www.the-digital-picture.com/Canon-Lenses/Canon-Lens-Aging.aspx


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## jdramirez (May 20, 2014)

Isn't the calibration Canon applying a micro auto focus adjustment? At f4, the depth of field is usually sufficient that your subject shouldbe in focus. At ff1.4, sure... but f4 is a while different animal. I'd be more concerned that the lens is off rather than the body and lens need to be paired.


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## neuroanatomist (May 20, 2014)

jdramirez said:


> Isn't the calibration Canon applying a micro auto focus adjustment?



No, they make electronic and/or physical changes in the lens to calibrate it to a standard body (and bodies are calibrated to a standard lens). They can make more sophisticated adjustments than AFMA.


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## mackguyver (May 20, 2014)

neuroanatomist said:


> jdramirez said:
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> > Isn't the calibration Canon applying a micro auto focus adjustment?
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A few years back, I sent in my bodies and a few lenses and for a rather hefty fee, Canon calibrated the heck out of my gear. In particular, the 5DII and 135 f/2 were stunningly sharp post-calibration. For my purposes, AFMA is pretty good, but I'm tempted to send in my 1D X, 300 f/2.8 IS II, and extenders. I've run them through FoCal twice, but I'm not happy with the results. I'm going to try again this week, but whatever Canon does is like AFMA on steroids.


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## BL (May 20, 2014)

jdramirez said:


> Isn't the calibration Canon applying a micro auto focus adjustment? At f4, the depth of field is usually sufficient that your subject shouldbe in focus. At ff1.4, sure... but f4 is a while different animal. I'd be more concerned that the lens is off rather than the body and lens need to be paired.



There are shims and spacers located in the mount and various other places in the lens. These often need to be replaced if the alignment is beyond the +/- 20 AFMA range.


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## Mt Spokane Photography (May 20, 2014)

If your lens is sharp when you focus using live view or manualy, it needs the focus adjusted. It can be the camera, the lens, or the combination of both.

There are two different things that might be needed. 

Autofocus adjustment involves a electronic adjustment to the AF data contained in a chip inside the lens. It can be adjusted at multiple places, and a lens usually benefits from a adjustment. They adjust it to a reference standard camera body of the same model, so give them the camera model you are using.

IF the lens is decentered (common in zooms), or otherwise out of adjustment, there are various mechanical adjustments.

If the lens mount is bent, it will vary in sharpness from side to side. The lens mount can be replaced and then shims might be required to get it exactly perpendicular to the optical center line. You cannot see a bent mount, it only takes a few tens of thousands of a inch. Its unlikely, unless the camera / lens was dropped.


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## pulseimages (May 21, 2014)

privatebydesign said:


> pulseimages said:
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Can't figure out that chart. ???


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## neuroanatomist (May 21, 2014)

pulseimages said:


> privatebydesign said:
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Scroll down to the list of letters. Your lens mount has U_#### where the _ is the year and the first two numbers are the month, e.g. UY08## is Aug 2010.


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## pulseimages (May 22, 2014)

OK, so the code on my lens mount looks like UB07## so it's July 2013?


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## neuroanatomist (May 22, 2014)

pulseimages said:


> OK, so the code on my lens mount looks like UB07## so it's July 2013?



Correct.


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## pulseimages (May 23, 2014)

neuroanatomist said:


> pulseimages said:
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> > OK, so the code on my lens mount looks like UB07## so it's July 2013?
> ...



Thanks!


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