Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 71,912   Posts: 1,584,693   Online: 681
      
Page 2 of 3 FirstFirst 123 LastLast
Results 11 to 20 of 24
  1. #11
    eSPhotos's Avatar
    Join Date
    Nov 2010
    Location
    Sydney Aust
    Shooter
    Multi Format
    Posts
    145
    If you're shooting stopped down and this happens then its symptom is known as 'front focus' - lens problem. However if it happens while aperture wide open (f1.4) then it is likely the fault is in the camera. As mentioned, the 28mm has much wider depth of field so you may not have noticed the same issue with the 28mm.

  2. #12

    Join Date
    Aug 2004
    Location
    Dunedin,New Zealand
    Shooter
    Multi Format
    Posts
    270
    I think,if we get more info ? Focus is out? -assessed at F1.4./F2 ?/F2.8 ?
    DSLR (Whoops,sorry) should be ok if it has a manual confirmation of focus mode. Use central focus spot -normally the most accurate.
    Another observation - the Nikon lens mentioned does NOT have a flat focus field - a poor choice for document copying for example..

  3. #13

    Join Date
    Aug 2004
    Location
    Dunedin,New Zealand
    Shooter
    Multi Format
    Posts
    270
    I think,if we get more info ? Focus is out? -assessed at F1.4./F2 ?/F2.8 ?
    DSLR (Whoops,sorry) should be ok if it has a manual confirmation of focus mode. Use central focus spot -normally the most accurate.
    Another observation - the Nikon lens mentioned does NOT have a flat focus field - a poor choice for document copying for example..

  4. #14

    Join Date
    Feb 2005
    Location
    Richmond, VA
    Shooter
    Multi Format
    Posts
    1,066
    Something bothers me about the set screw suggestion - if the focusing ring was out of position, it would display an incorrect distance, but the problem isn't the distance displayed vs the real distance, it's that when the image is focused on the ground glass in the pentaprism, it isn't focused on the film. Moving the focus ring will change the indicated distance, but won't affect the GG / film plane problem. Am I missing something?

    What model is the camera?

  5. #15

    Join Date
    Apr 2004
    Location
    Montgomery, Il/USA
    Shooter
    Multi Format
    Posts
    5,310
    Quote Originally Posted by George Collier View Post
    Something bothers me about the set screw suggestion - if the focusing ring was out of position, it would display an incorrect distance, but the problem isn't the distance displayed vs the real distance, it's that when the image is focused on the ground glass in the pentaprism, it isn't focused on the film. Moving the focus ring will change the indicated distance, but won't affect the GG / film plane problem. Am I missing something?

    What model is the camera?
    First camera was a dig*, second was an F3.
    Thinking(?) about it you may very well be correct.

    I understand the problem to be>In focus through VF, oof at film. The indicated distance isn't a problem. The test he's doing is at close distance.
    I think I would verify that infinity focus is accurate first. focus at film plane, then check VF. If they DISAGREE, adjust the focusing ring.

    FWIW Practical infinity is around a block away, theoretical is 500 or 1000 times the focal length. top of an antenna/water tower, high building etc.

    I'm wondering if it's a problem with the error on the electric camera and shimming of some sort. I understand there are a lot of the Voigtlander and FSU lenses that need to be shimmed to focus properly on those things.
    Heavily sedated for your protection.

  6. #16

    Join Date
    Feb 2008
    Location
    Winnipeg, Canada
    Shooter
    Multi Format
    Posts
    1,301
    The focus test should compare the image, viewfinder and the autofocus confirm light. If the image agrees with the focus confirm light, then the discrepancy lies in the viewfinder and operator.
    Bob

  7. #17
    darinwc's Avatar
    Join Date
    Dec 2003
    Location
    Sacramento, CA
    Shooter
    35mm
    Posts
    2,090
    Images
    159
    If the AI conversion was aftermarket, or if you are using a poorly designed adapter, it is possible the lens is not parallel to the film/sensor plane.
    Alternatively, it may also be that the lens is not assembled correctly and it is not as sharp as it appears in the virefinder. it is very hard to judge sharpness in the viewfinder.
    Go not to the elves for counsel, for they will say both yes and no.

  8. #18

    Join Date
    Apr 2008
    Location
    Los Angeles, CA
    Shooter
    Multi Format
    Posts
    8,021
    Images
    4
    The stock focusing screens (and all but a few optional ones) for AF cameras are cut with a pattern that is optimized to be nice and bright for slow lenses. That is great if you use slow lenses, but not if you use fast lenses. The screens will generally show you the D of F and viewfinder brightness at f/2.8 or higher, regardless of how fast your lens is. This means that when using lenses faster than f/2.8 in very critical focusing (up close wide open, for example), things can appear tack sharp in the viewfinder when they are not really tack sharp at the focusing plane. It happens all the time with my 50mm f/1.2 on my 10D. Try using your focus confirmation dot in the camera and see if it helps. I have learned through experience to use that dot whenever possible if I am using a lens that is faster than f/2.8.
    Last edited by 2F/2F; 07-30-2011 at 06:06 AM. Click to view previous post history.
    2F/2F

    "Truth and love are my law and worship. Form and conscience are my manifestation and guide. Nature and peace are my shelter and companions. Order is my attitude. Beauty and perfection are my attack."

    - Rob Tyner (1944 - 1991)

  9. #19

    Join Date
    May 2006
    Location
    Aurora, IL
    Shooter
    35mm
    Posts
    1,990
    If the OP eyesight is very good (i used to have such eyesight hichic) then I think the problem is with the camera. The op didn't actually shot some film with the F3 and see if he has the same problem.

  10. #20

    Join Date
    Jun 2003
    Shooter
    Large Format
    Posts
    16,887
    why don't you bring your camera+lens in person to a repair shop
    drop it off and get a free estimate to see what is wrong with it ...
    instead of having every one here make suggestions as to what *might* be wrong.
    an estimate is usually free, and repair people will have the camera+lens in hand
    and be able to tell you exactly what is wrong ... instead of a guess.

Page 2 of 3 FirstFirst 123 LastLast


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



Contact Us  |  Support Us!  |  Advertise  |  Site Terms  |  Archive  —   Search  |  Mobile Device Access  |  RSS  |  Facebook  |  Linkedin