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Sigma 10mm Fisheye on Pentax KP

Discussion in 'Pentax Chat' started by steeplejack, Aug 29, 2019.

  1. steeplejack

    steeplejack Member

    I have an early model Sigma 10mm Fisheye Pentax mount serial 1008941 which worked well on earlier Pentax models but plays up on the Pentax KP - hunts, seizes up the shutter, can’t alter the aperture. Is this a known problem and is there a solution? Other lenses work ok. Thanks for any advice.
  2. El_Sid

    El_Sid Well-Known Member

    Sounds very similar to the issues we Canon users have encountered with Sigma. I have a number of early Sigma lenses that will only work properly with older, mostly film, EOS models - use them on anything they're not compatible with and they will lock up the camera.

    The usual answer was to send them back to Sigma to be re-chipped for later models. It might be worth contacting Sigma to see if this is still an option for your lens but if the lens is fairly old then it's possible re-chipping is no longer possible...:(

    Do you still have an old body that it' works on? That may be your only solution, in my case I have a digitally ancient EOS D30 that works with mine if I need to use them.
  3. Chester AP

    Chester AP Well-Known Member

    I assume 'hunts' refers to autofocus: I get the same problem if I make the mistake of leaving my Sigma 10-20 zoom on autofocus for landscape shots. It's only worth using autofocus for close subjects and using spot focusing. I suspect the problem is that there's so much sky in the shot that anything apart from close subjects and spot focusing confuses the autofocus.

    Re. the aperture and shutter problems: all I can suggest is checking that all the contacts on the lens and the camera body are clean. I once had problems like this with a very old Tamron 90 mm lens, but a few moments with a cotton bud and a very small amount of surgical spirit fixed it.
  4. steeplejack

    steeplejack Member

    Thanks for these suggestions. I returned the lens to Sigma who upgraded the firmware and returned it within a week without charge, apart from postage. Great service!
  5. El_Sid

    El_Sid Well-Known Member


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