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  1. #11

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    if you are focusing with a tripod and everything is fine
    and hand held it is slightly out of focus, at f4, it seems that
    you have moved, or your subject has moved, ( or both ) so your focus
    is a little off ... this is the same problem a lot of people have with LF ...
    especially when one has to focus, stop lens down, insert film, pull dark slide
    and make the exposure ( and the camera is usually on a tripod ) ...
    maybe rollei suggests focusing on the nose to compensate for people moving forward
    just a tiny bit, when someone is taking their portrait ...


    john

  2. #12
    fotch's Avatar
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    That is a rather heavy camera to hand hold and shoot, at low shutter speeds. If photos are sharp on a tripod, then it is not a camera problem, rather, it is a photographer problem. JMHO
    Items for sale or trade at www.Camera35.com

  3. #13
    martellsv's Avatar
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    The eyes seem pretty sharp.
    IMHO, It could be camera digital reproduction excessive focus not a lot, and the lith help sommthing
    That is a rather heavy camera to hand hold and shoot, at low shutter speeds. If photos are sharp on a tripod, then it is not a camera problem, rather, it is a photographer problem. JMHO
    I usually have the same problem, exactly out of focus the defocus distance.... i donīt know how focus tha subject
    to be sure tha exposure is ok, nowdays is a lottery ... always the same error
    this is a headache...

    NOw i am sure i have no problems with the screen, itīs correct thanks a lot J.

    any recomendations? this afternoon i will try again, with my son, same conditions
    Last edited by martellsv; 09-24-2012 at 09:18 AM. Click to view previous post history.

  4. #14
    ic-racer's Avatar
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    When the film bulges in the film gate the focus will shift behind the subject.
    You can confirm if the is the problem by taking the lens off and exposing at "B" with film in the film gate. When you touch the tip of a pencil to the film it should not move if it is against the pressure plate. If you see the film move or indent when touched with the tip of the pencil, the film is bulging.

    The cure for this is to shoot 4x5 film That is what I do when I don't want to be bothered by rollfilm flatness.

  5. #15
    RalphLambrecht's Avatar
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    please elaborateon'chemical focus!
    Regards

    Ralph W. Lambrecht
    www.darkroomagic.comrorrlambrec@ymail.com[/URL]
    www.waybeyondmonochrome.com

  6. #16

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    Quote Originally Posted by RalphLambrecht View Post
    please elaborateon'chemical focus!
    Early plates were sensitive to blue-to-UV light. These wavelenths of light come to a different point of focus than the greenish wavelengths the eye is most sensitive to. So there was a visual focus and a chemical - sometimes called actinic - focus with the early non-achromatic lenses.
    In diminishing wavelength (or increasing frequency) the colors of light are (infrared)red-orange-yellow-green-blue-indigo-violet(ultraviolet).
    Last edited by E. von Hoegh; 09-25-2012 at 10:59 AM. Click to view previous post history.

  7. #17

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    Quote Originally Posted by RalphLambrecht View Post
    please elaborateon'chemical focus!
    Ralph,

    It's a combination of two things. Some paper's sensitivity to UV and some lenses inability to focus UV at the same plane as other colors in the visible spectrum (which we use to focus).

    Ctein elaborates on this in his "Post Exposure."

    This was more of an issue in the past, and one of the reasons that blue filters came with some grain-focusing devices; by focusing on with blue, you'd be closer to the focus of the UV.

    Nowadays this is rarely an issue: most lenses are better corrected and most papers are no longer so sensitive to UV. Plus, if one stops down a bit, which seems to be the practice more now than in the past, since papers are faster, you get a considerable depth of focus at the enlarging easel which alleviates this effect.

    FWIW, I don't think the OP's problem has anything to do with chemical focus. Likely just difficulty hand-holding.

    Best,

    Doremus


    www.DoremusScudder.com

  8. #18
    martellsv's Avatar
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    I was using SL66 and "45 degree prism"f/4 1/60 with a magazine 6x4.5 TMAX 100, and not the usual Waist Level and 400 ISO, dificult to get sharpness, precision ... with focus at some situation, portrait with SL66 and "45š degree" i donīt like Likely with hand-holding.

    of course ... waist level is far better, it could help a 400 iso film and not 100... thanks

  9. #19
    martellsv's Avatar
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    I was using SL66 (the camera about three kgrs.) and "45 degree prism"f/4 1/60 with a magazine 6x4.5 TMAX 100, and not the usual Waist Level and 400 ISO, dificult to get sharpness, precision ... with focus at some situation, portrait with SL66 and "45š degree" i donīt like Likely with hand-holding. IMHO waist level is far better, it could help a 400 iso film and not 100... thanks

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