Weird issue with Sigma Lens

Discussion in 'Photography Equipment & Products' started by JonA_CT, Jan 8, 2016.

  1. JonA_CT

    JonA_CT TPF Supporters Supporting Member

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    I have a Sigma 17-70 2.8 Lens that I've been seeing some weird stuff out of -- wondering if it's broken or maybe if there is another issue.

    I noticed recently that when in Manual or Av mode on my camera, I can't select F2.8 as an option at 17mm. I can only get to F3.2. I started to dig around in EXIF data, and noticed that photos when the indicator on the lens says I should be at 17mm, it reads 21mm, and when I should be at 70mm, it's only reading 57mm.

    I guess my question is whether this a software issue or an issue or an issue with the lens. If it is something with the lens, is it worth having it sent out for work, or should I be looking for something different?


     
  2. Overread

    Overread has a hat around here somewhere Staff Member Supporting Member

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    Try cleaning the copper contacts on the lens and on the body in the lens mount area. Could just be a bit of dirt is causing a miss-communication between the two. The eraser end of a pencil can do a good job of cleaning the contacts.
     
  3. beagle100

    beagle100 Been spending a lot of time on here!

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    strange, maybe try comparing a shot with a lens you know is f2.8 17mm with the Sigma at f3.2 17mm
     
  4. Peeb

    Peeb Semi-automatic Mediocrity Generator Supporting Member

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    any luck?
     
  5. JonA_CT

    JonA_CT TPF Supporters Supporting Member

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    Sorry, I evidently had typed a response on my phone but never sent it. I've tried cleaning the contacts, and it really hasn't changed much. I've been having AF issues with all of my lenses so I'm wondering if it's an issue with the camera. I'll be seeing a friend this week that has another EF-S mount camera, so I'll bring my lenses with me and see if it is different.
     

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