1. Reminder: Please user our affiliate links to get to your favorite stores for holiday shopping!

150mm f2 front focus

Discussion in 'Adapted Lenses' started by alexz, Feb 20, 2013.

  1. alexz

    alexz Mu-43 Rookie

    11
    Feb 20, 2013
    I have place the Zuiko 150mm f2.0 on my OMD with the MMF-3 adapter.

    The image quality is amazing in manual focus.

    In AF, I always have front focus, approximatively 2cm per meter (thus 1 inch every 3 or 4 foots), at short or long distance.

    I have seen that it could be sperical abberation, but no difference at f2 or f11 !

    The error seems regular, would it be possible to make a adjustment on the lens ? Thanks in advance.
     
  2. MAubrey

    MAubrey Photographer

    Jul 9, 2012
    Bellingham, WA
    Mike Aubrey
    I still think that its just misfocusing...like I said I DPreview. The nature of CDAF is that its going to go past the focus point to confirm what sharpest and then coming back to correct. It sounds like its just correcting too much. This is what my 50-200mm does.

    Maybe check to see if the in front of the subject miss is a result of the focus point starting in front of the subject. Does still focus in front of the subject when you start focusing from infinity behind the subject?
     
  3. alexz

    alexz Mu-43 Rookie

    11
    Feb 20, 2013
    Thanks MAubrey, I also think that it's just correcting too much.

    Concerning the focus direction, it sounds like a good idea, I'll try it tomorrow !
    Does it work better in one direction with your 50-200 ?

    I also have to precise that, despite the front focus, the image quality is still great in autofocus, with the help of a sharpening treatment :
    [​IMG]
    (without sharpening, only the nose is sharp)
     
  4. alexz

    alexz Mu-43 Rookie

    11
    Feb 20, 2013
    At longer distance, i have to put more sharpening to correct to front focus :
    [​IMG]
    (here you see that the grass is sharper 2 inches in front of the duck. Without sharpening, the grass is sharp, but not the duck)
     
  5. MAubrey

    MAubrey Photographer

    Jul 9, 2012
    Bellingham, WA
    Mike Aubrey
    Good question. Off the top of my head, I'm not sure. I'll have to check that...