Bad lens??

Discussion in 'General Shop Talk' started by perfectcircle, Sep 25, 2009.

  1. perfectcircle

    perfectcircle TPF Noob!

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    Ok I just recieved my Sigma DC 17-70mm 2.8-4.5 macro lens.. My issues is at 17mm I cannot get the a/f to go any lower than 4?? And it also says that the maximum a/f is 22 but it'll go all the way to a/f 32.. My camera is a Sony A200.
     
  2. chakalakasp

    chakalakasp TPF Noob!

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    Are you trying to get your aperture below 4 when zoomed out to 17mm? Because the aperature should only go down to 2.8 when at 17mm. As you zoom in, the minimum aperature size decreases towards 4.5.
     
  3. perfectcircle

    perfectcircle TPF Noob!

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    That's the problem, it won't open all the way to 2.8 at 17mm it'll only open to 4
     
  4. Big Mike

    Big Mike I am Big, I am Mike Staff Member Supporting Member

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    Look into the lens to see if the aperture is actually open all the way (you may have to use DOF preview to see it stopping down first).

    Just off the top of my head, it might be an issue with the communication between the lens and camera...where the lens is telling the camera it's wide open, but the camera is only reading that as F4.
     
  5. perfectcircle

    perfectcircle TPF Noob!

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    I'm not really sure how to tell if the aperture is open all the way.. Also the A200 does not have a dof preview button unfortunately
     
  6. perfectcircle

    perfectcircle TPF Noob!

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    Called the place where I bought it from and the guy said it sounded like a defective lens. So he is shipping me another one out with a return label so I can send the bad lens back. Thought that was nice of them to Ship me one out instead of having to wait around for the bad one to make it back..
     

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