Can a Rolleiflex be out of focus calibration?

Discussion in 'Medium Format Cameras and Accessories' started by NortheastPhotographic, Dec 28, 2017.

  1. NortheastPhotographic

    NortheastPhotographic Advertiser

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    I am getting a fair amount of back focus with my 2.8E, mostly close up with apertures of 4.0 and 2.8. Now I'm working with a Maxwell screen and a Hasselblad prism finder, and focusing carefully. This happens more than I feel like is normal for hits and misses frankly. Could my screen be slightly out of alignment? If so, is this something I can rectify myself, and how so?

    Thanks!
     
  2. RalphLambrecht

    RalphLambrecht Subscriber

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    Yes, and it could happen with a brand-new camera. self -adjustment is possible but not easy. Find a good repair shop.
     
  3. shutterfinger

    shutterfinger Subscriber

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    To set up focus on a camera
    1. mount the camera on a sturdy tripod.
    2. with the lens wide open focus on an infinity target at least 5000 feet away at the film plane using a good loupe. The further the infinity target the better.
    3. adjust the focus screen or ground glass to match the film plane focus using a good loupe.
    4. paper or brass can be used for shims to shim the focus screen if no adjustment post/screws are used.

    A Rolleiflex service manual is available for free at http://www.kyphoto.com/classics/repairmanuals.html , be sure to follow the download instructions at the top of the page.
     
  4. Xia_Ke

    Xia_Ke Subscriber

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    When you focus to infinity, is the front face flush to the body all the way around? I bought one years ago that turned out to have been dropped, which threw the taking lens out of alignment with the viewing lens. At least that was what Krikor said when I sent it in for repair. When focusing to infinity you could see the top was canted forward just slightly. Luckily I got it from an honest seller and I was able to get my money back.
     
  5. ic-racer

    ic-racer Member

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    On my 2.8F the collimation was off. Which is to say the infinity stop was not at infinity. That is pretty easy to fix (adjust the focus knob after removing the meter module) and I have resolved this issue. However, looking back at some landscape work I did in the 1980s, I see I just racked to focus to infinity, rather than focusing at infinity, and those images are not sharp. In my case the infinity stop allowed it to focus beyond infinity which is one of the worst things that can happen. Now that it is fixed, I can just rack it to infinity and it is OK.
     
    Last edited: Dec 28, 2017
  6. OP
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    NortheastPhotographic

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    I was just about to mount the camera on a tripod until I realized that I have to take the tripod mount off the camera to install a ground glass to the taking lens...any workarounds for this?
     
  7. ic-racer

    ic-racer Member

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    I have never come across a TLR with the lenses focusing at different positions from the factory. If you have not disassembled the camera, or dropped it, it is likely not needing recalibration.

    Items that more commonly would be amiss:

    Film Bulge
    Mirror loose or out of correct position
    Ground glass out of correct position


    In terms of film bulge, 120 film is notorious for not laying flat. Some film worse than others. Some cameras worse than others due to the curve imparted by the film path.
    If the film bulges off the pressure plate that image will be focused beyond your intended focus. It is always BEYOND the intended focus, because, unless your pressure plate is damaged, the film can't bulge backward. You can blame it on the film or blame it on the camera.

    Of course if you focus is IN FRONT of your intended focus you can rule out "film not flat."
     
    Last edited: Dec 28, 2017
  8. shutterfinger

    shutterfinger Subscriber

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    I would mount a piece of wood that is flat to the tripod then sit the camera on the wood and tape the sides to the wood with wide painters tape to keep it in place.
     
  9. shutterfinger

    shutterfinger Subscriber

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    Some camera manufacturers use paper shims on their focusing panels while others use posts with rubber caps. The paper and rubber will deteriorate over time and vibrations from handling will cause threadlocker to break loose if a thin coat was used.
    So far you've been lucky.
     
  10. Sirius Glass

    Sirius Glass Subscriber

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    The body could be out of alignment or the viewing screen is not in the proper location. Have a repairman mad the appropriate adjustments.
     
  11. Chris Livsey

    Chris Livsey Member

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    This man knows his Rolleiflexes:
    When many people are looking for a new screen it is because they are experiencing a focus problem.
    - Finding a Rolleiflex that is within factory focusing tolerance is a rare occurrence.
    - In most cases, both lenses need to be adjusted.
    - There are differences in the focus adjustment among screens . This is true of a the original factory screens and non-factory replacement screens.
    http://www.rolleirepairs.com/maxscreen.htm

    You have a Maxwell screen, was it installed as a drop in replacement without checking calibration? I think you have your answer if the reply is positive to that question. If no, it was calibrated, whoever did it needs to check again or get someone who knows what they are doing. Taping to wood and fiddling with the focus is only delaying sending it to a pro unless you are really, really lucky, do you feel lucky?
     
  12. Sirius Glass

    Sirius Glass Subscriber

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    Even Hasselblads need to have the camera body adjusted for focus. Any camera can get out of alignment.
     
  13. ic-racer

    ic-racer Member

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    The 2.8E has neither fiber washers or rubber. The 4 washers available (0.2-0.8mm) to adjust lens board parallelism would not be expected to compress with time. However, the OP has not mentioned if the camera has been tampered, or damaged.
     
  14. shutterfinger

    shutterfinger Subscriber

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    In his initial post he states it has a Maxwell screen and Hasselblad finder therefore its modified.
    If the focus error cannot be corrected by adjusting/shimming the view screen, which is an easy task, then its time for the shop with the alignment equipment.
     
  15. OP
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    NortheastPhotographic

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    Well I checked focus with a spare ground glass and a loupe. It appears to be in calibration... Meaning it's probably me. I just don't remember it being this difficult to focus at 2.8. Maybe next time it needs a CLA I'll send it to Fleenor to be sure. It's very frustrating.
     
  16. shutterfinger

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  17. Dan Daniel

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    Hand held? It's quite easy to move your body and the camera enough to go out of focus between getting focus and reframing for the final shot. An 80mm lens at 2.8 or 4 doesn't have much depth of field close up.

    By any chance does your screen have a split image? A few years ago in conversation with Bill Maxwell he specifically recommended against buying his split image screen if doing close work. The split image circle almost requires that you put the split on your main subject, focus, then reframe. And in this reframing, especially handheld, people move. Enough to throw focus off. Maybe more attention to your body movements while shooting will help?
     
  18. ic-racer

    ic-racer Member

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    I don't know about the Maxwell screen, but I only used my Beattie Intenscreen for a short time because it was way too difficult to focus. The point of exact focus on the screen was very vague and covered a lot of distance on the focus knob. I went back to the original Rolleiflex screen; it showed the exact focus point better, even though it was dimmer. My Beattie screen reminded me of the "Bright" finder lever on my Beaulieu 8mm camera. It was essentially a clear or lightly frosted screen for viewing and not focusing; similar to an arial image.
     
  19. OP
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    NortheastPhotographic

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    I did it with the Rollei sitting on a table, and the spare screen taped in. I am going to try again using a vice to lock the Rollei in place.

    Now one other thing I noticed...and you're going to laugh at me...my pressure plate was in 24x36 setting... ****DUCKS****

    I also happen to own a Lens Align kit. I'm going to focus on one from 4 feet tomorrow and process the film right away (it's good to own a lab). The lens align makes it easy to focus on target and see the DoF.
     
  20. Dan Daniel

    Dan Daniel Subscriber

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    A VISE???? No, you don't mean this, right? This is a focus test, not a missile test firing. A piece of tape on the table is fine.

    When I asked about your screen, I was referring to the actual focus screen in the camera. Not the ground glass you are using for your testing. Everything I was saying was about a split image screen installed in the camera.

    Use ground glass on the film plane. No split image, no microprisms. Plain ground glass, a Mamiya A screen, or such.

    You can simply run a roll of film through a machine? Then yes, skip the film plane testing. Use just the focusing screen installed in the camera. Shoot the test target. See where focus ends up. If focus on film is closer to the camera, you need to move the screen away from the mirror- put scotch tape on the bottom of the metal focus hood edges after removing it from the camera (I'm assuming non-removable hood that needs the four screws removed to get access to the screen). If focus on film is behind the target point, you need to move the focus screen closer to the mirror. Scotch tape along top and bottom edge of the actual screen be careful- top surface of a Maxwell is VERY delicate, do not touch).

    As a starting point for shimming, a Maxwell screen is going to run about .006" to .012" thicker than the original ground glass. I think these numbers are close if the original screen was a Rollei plastic fresnel screen, also.

    All of this is easier if you have the lens shroud off and can simply screw the viewing lens in and out but then you have the depth of field indicator to reset on assembly, etc.
     
    Last edited: Dec 30, 2017
  21. ic-racer

    ic-racer Member

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    What Dan said and use 1/p+1/q = 1/f to find out how much tape you need to shim the screen.
    p = focal error behind subject (mm)
    q = focal error at film plane (focus screen) (mm)
    f = focal length (80mm)

    You can wind ten turns of tape around a pencil and measure it. Divide by 10 to get the thickness of the tape (shim).
     
  22. paul ron

    paul ron Subscriber

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    AS everyopne has already said... you need to check the film plane to the VF GG. Put GG on the film plane rails using a small piece of tape. Focus at infinity in teh VF and using a loupe, check the film plane GG. Do this test with and with out the prism.

    Ive had many cameras come to me saying they were out of focus but when putting them on the collimeter I see they are in alignment. the cause is the person focusing needs a correcting diopter.

    also mentioned, the bright screen needs to be adjusted when installed and that can be your problem.... that's checked film plane to taking lens but without the prism present.

    that adapted prism may not be focusing on the screen properly. Thats an easy check though. facing a well lit blank wall, put the lens out of focus.... when looking in the prism, is the focusing screen markings sharp? Diopter is the correction then.
     
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