Canon problem: help me figure out what’s wrong!


Taken at 1/200s f3.5 with 70-200/2.8 II lens on 50MP 5DS R body. Images stabilization on in handheld mode.

Taken at 1/200s f3.5 with 70-200/2.8 II lens (actual focal length 105mm) on 50MP 5DS R body. Images stabilization on in handheld mode. Same problem shows up with 1/640s exposure or with studio flash.

I have no idea what’s wrong. All other lenses work fine on 5DS R body. The lens in question works fine on 5Dmk2 and Sony A7R bodies. But the two aren’t working on combination. Camera firmware is up to date. Canon Professional Services have no guesses. The combination as it is now is useless for any purpose.

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8 Responses to Canon problem: help me figure out what’s wrong!

  1. Chris says:

    Send the lens and body to Canon for tweeking. Looks like they aren’t lining up properly.

  2. RB says:

    A couple of questions:

    1) Does the direction of aberration change at different zooms/ focal lengths (i.e. in the kahles example the aberration is in the 11-o-clock ish direction )?

    2) does the aberration go away if you put a doubler in- line?

    3) Does the problem occur with IS off?


  3. Paul Koning says:

    It’s hard to judge this without knowing which part of the image that “kahles” thing is taken from. It might be informative to take a photo of a test pattern, to see what you’re getting at various points in the image. It looks a bit like either coma or astigmatism, which suggests a misaligned optical axis. Is there some damage on the mount lugs that tilts the lens when installed?

  4. Will says:

    I would mount the setup on a tripod, and shoot the same distance with, and without, the IS engaged.

    You need to check/change one variable at a time.

    Repeat the same test with your hands holding the camera while still on the tripod.

    What you want to define is whether the problem is entirely an optical/element effect, or electronic. The third possibility is some sort of interaction of the first two. It would be useful if you had an identical body or lens to compare, to see if the problem follows one or the other.

    Rotating the camera setup by 90 degrees and checking if the effect follows, or changes in any way, would be one of the checks. (gravity check of any mechanical elements)

  5. David says:

    Do you have a focus micro adjustment setting for that lens? I don’t know how to check for that on a Canon, but I had a friend who was playing around in the camera menus and messed things up good setting that adjustment. And it was lens & body specific, of course.

  6. Gewehr98 says:

    I’ll echo what David said. I know for my Nikons, I can make fine focus adjustments for each lens that gets mounted to the body, and the body will retain that focus setting indefinitely. If you find you’re consistently back-focusing or front-focusing with a given lens, it may be something to explore.

  7. Oleg Volk says:

    Canon sent me a note that 70-200 required repair. Don’t know the details yet. $311.

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