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  1. #1

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    Mamiya 645 Pro Focusing repair needed - Los Angeles

    Hi, brand new to the forums here.

    I recently purchased my first MF, a Mamiya 645 Pro, and took a few rolls of portraits. I was very careful to use the split-screen, harkening back from my old Canon 35mm days. Most of the photos returned back-focused. Although I was mostly wide open, it was consistently behind my intended focal point.

    I shot a quick test roll yesterday, tripod mounted and it seems that indeed the prism back focuses. I've read this could be mirror alignment, a curved focusing screen, or misalignment/installation of the focusing screen.

    Can anyone recommend a Los Angeles area camera repair shop that can address this?

    OR, is there another route I should take first?

    Thanks!

  2. #2

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    Steve Choi: www.stevecamera.com

    Lenor, in the Melrose area

    Samy's Camera, several locations

    Pro Camera Service, Thousand Oaks

  3. #3

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    Brian, thanks for the quick reply.

    I called Steve first, very friendly & helpful person. Unfortunately, he told me they or no one else have the alignment tools necessary to check a Mamiya.
    But, he gave the me the contact info for their repair department back in New York. I just spoke with a guy there who was also quite helpful and recommended shipping it to them to check and repair.

    For reference, in case someone else searches for this (and perhaps this forum has already covered this a thousand times before):

    Mamiya's number is: 914-347-3300
    and
    he said the issue could not only be the mirror or focusing glass, but could also be the lens, back, or even the insert.

  4. #4

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    Hello;
    I would think that the lens was serviced at some point and the helical was not correctly ajusted. To check this, focus on an object about 1/4 mile away. If there is any play left on the focus ring, this is the culprit. All camera's are adjusted at infinity. Check if the focus screen is in place. These were interchangable. Is the film back on securely? Did you place the film insert in correctly, should be a click of the two locks. The Mamiya tech is correct and send all components. Steven.

  5. #5

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    Hi. Thanks for the additional info. I just tested the lens per your recommendation, and it appears to be fine and solid at infinity.
    The focus screen is what I first looked at, and it too seems to be solidly in place. The focus issue has happened with 2 separate film backs, but I only have a single 120 insert to test them with. My guess is that it leaves the issue to be the insert or the mirror.

    Question: When loading the film on the insert, how tightly should the film be stretched on the insert once rolled up to the starting arrow? Is some bow/arcing ok, I would think this is flattened be what appears to be two small rollers on each side of the inside of the back (top and bottom of the hole through to the shutter). Or should the rollers on the insert be pulling the film completely taught?

    I'm finishing up another test roll today, then I'll load a new roll and snap a dig pic of what I'm speaking of.

  6. #6

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    Hello;
    Look at the film insert carefully! Does the film pressure plate have enough tension? Beneath this is a flat spring with the edges turned up to apply pressure. Is the film insert correctly locking into the back? There is one lock on each side that must click into position. Also check for bits of backing paper that could be blocking the insert. You could also get a 220 back and remove the plastic interlock wedge on the side, which turns this into a 120 back. The backing plate has two grooves cut in allowing the plate too set closer in on the film rails thus applying more pressure on the backing paper. The film when loaded should be tight, no flopping. Hope this helps, Steven.

  7. #7

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    I need to finish this test roll still before I can inspect the insert again, but I'm really wondering if you are correct about it. Either way, I just ordered a few brand new inserts from Ebay, I needed additional 120's anyway. I'll still post pics soon.

  8. #8

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    Amazingly, I have already received those brand new inserts. Unwrapped the first one, and while loading a new roll of film found it to be MUCH tighter, and slightly more difficult to roll, meaning it required more force to pull the film across while spinning the take up spool. Shooting a test roll soon with the f/1.9 lens again.

    I shot a roll with the f/2.8 kit lens, and it didn't seem to backfocus, but that's difficult to tell with a cheap development locally and a quick scan myself. Especially at f/2.8. This initially led me to think though that it was the f/1.9 lens. But that tension on the new insert really speaks volumes, giving it a try today.

  9. #9

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    I had front-focus problem whith mine 645 super. It was just the mirror that needed to raise a little bit. Very easy to adjust,there is a tiny little hole in front low right.
    The screw is locked by a lot of black glue or something. No problem, if the screwdriver fits perfekt.
    In case of frontfocus and to raise the mirror, turn left. Backfocus will be opposite. Very simple mirrorstop in these cameras and easy to adjust, one plastic piece, a spring and one adjustmentscrew.

  10. #10

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    Thanks for the heads up! I'm still thinking it was the insert, but I'm actually shooting one more test roll today and taking it to RPL to verify. I appreciate the DIY solution if it turns out to be the mirror though, I've realized the Mamiya tech fix in NY is actually more expensive than just buying a new body from KEH!



 

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