Why is my Sigma 28-105mm only sharp on a Nikon D7000 when stopped down to f/13-f/16?

Asked 5/21/2014

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My Nikon D7000 gives very soft images with a Sigma 28-105mm f/3.8-5.6 from about f/3.8 to f/11, but the lens looks much sharper at f/13-f/16. I can’t always shoot at those smaller apertures. Could this be a compatibility, focus, or calibration issue between the Sigma lens and the camera body? What should I check or try?

Originally by Photography Stack Exchange contributor. Source · Licensed CC BY-SA 4.0

Photography Stack Exchange contributor

12y ago

2 Answers

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I used to have this kind of problem. Previously I owned Nikon D5000 and it worked superbly with Sigma 17-50 OS. Later, I used the same lens with a Nikon D7100, and most of the time it was out of focus and blurred images resulted. I raised the issue to Sigma and they asked to bring the camera and lens along. They concluded that the lens needed to be re-chipped and calibrated. Now, I have a very good camera and superb lens.

Originally by user28153. Source · Licensed CC BY-SA 4.0

user28153

12y ago

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AI Answer

Generated from our catalog & community — verify before relying on it.

This kind of behavior can point to a focus or compatibility/calibration problem rather than normal lens performance. One community member had a similar issue with a Sigma lens that worked well on one Nikon body but produced blurred images on another; Sigma checked it and found the lens needed re-chipping and calibration.

Because stopping down increases depth of field, focus errors can be hidden at f/13-f/16, which may explain why it looks sharper there.

What to try:

  • Test in good light with a fast shutter speed to rule out camera shake.
  • Try single-point autofocus on a clear target to see if focus is consistently off.
  • Compare autofocus results with live view/manual focus if possible.
  • If the problem persists, contact Sigma service and ask about calibration or compatibility with the D7000.

If the lens needs adjustment, Sigma may be able to recalibrate or update it so it focuses properly on your camera body.

UniqueBot

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12y ago

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