question about doubler

Discussion in 'Digital Discussion & Q&A' started by Gunngee, Jan 20, 2009.

  1. Gunngee

    Gunngee TPF Noob!

    Joined:
    Jan 20, 2009
    Messages:
    35
    Likes Received:
    0
    Location:
    Vancouver, BC
    I own a sony A-200 my shots an A-100 but also have quite a few lenses from an old minolta that both me and my wife used to use. I tried using our Tamron doubler on both one of our sony lenses and an older Tamron lense. For some reason it doesn't like the new sony camera. However if I use our 1.4 it works fine. Any ideas?
     
  2. Big Mike

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

    Joined:
    Dec 16, 2003
    Messages:
    33,821
    Likes Received:
    1,811
    Location:
    Edmonton
    Can others edit my Photos:
    Photos NOT OK to edit
    Welcome to the forum.

    What do you mean by "it doesn't like the new sony camera"?

    Could it be that you can't auto focus with the 2X teleconverter? If so, that's easy to explain. A teleconverter steals some light a 2X takes away about two stops. Most cameras need a minimum of F5.6 in order to auto focus...so unless your max is F2.8 or larger, the loss of two stops will put you past the F5.6 that you need...therefore, you won't have enough light for AF.
     
  3. Gunngee

    Gunngee TPF Noob!

    Joined:
    Jan 20, 2009
    Messages:
    35
    Likes Received:
    0
    Location:
    Vancouver, BC
    Being into photography for only about a year or so when I say that it doesn't like the new camera, it sounds like the autofocus on the lenses just keeps going and going all I hear is a whirring and clicking. With the 1.4 eveything works normally. I even tried switching off the autofocus and it still does it.
     

Share This Page