1. Reminder: Please use our affiliate links for holiday shopping!

Canon 300mm L f4 lens issue

Discussion in 'Adapted Lenses' started by Gary Ramey, Aug 19, 2013.

  1. Gary Ramey

    Gary Ramey Mu-43 Veteran

    240
    Dec 27, 2012
    Aurora Colorado
    When I first got this lens I had no issue at all and it was tack sharp at all f stops. Lately, and after a trip in a suitcase, the lens doesn't want to focus to infinity on my OMD. Is there the possibility the lens mechanics are bad? It still feels smooth with no issues. I'm a little bummed because I was having a great time with this lens. Any suggestions?
     
  2. meyerweb

    meyerweb Mu-43 Hall of Famer

    Sep 5, 2011
    Do you have access to a Canon camera to test the lens on?
     
  3. MitchHamilton

    MitchHamilton Mu-43 Regular

    40
    Feb 16, 2010
    Banff, Alberta, Canada
    Is it the FD version or the EF version? Check that you don't have build up on the adapter, even a millimeter of variance on the adapter can throw infinity focus off.
     
  4. Gary Ramey

    Gary Ramey Mu-43 Veteran

    240
    Dec 27, 2012
    Aurora Colorado
    Thanks, it's Manuel focus and aperture. What happened is there is a little screw that goes through a plastic standoff that moves the focus when you rotate the barrel. That screw was stripped. The only way to replace it was a complete disassembly...which I attempted. I fixed the focus but was unable to get the aperture ring in place and working so I simple removed it and shoot the lens wide open.