Mamiya 645 PRO focus

stavrosk · Dec 22, 2011

I recently bought a Mamiya 645 Pro and I was wondering, is it possible that there is a problem with the camera otherwise not visible that can affect the focusing?
It seems like the focus from the few portraits I got back from my first roll is some few cm back from where I intended?
I am not sure I did everything right, so I had a test roll with specifically very selective focus that is currently at the lab so I can be sure.
I just wanted to know if there even is such a possibility.
Thank you

Shawn Rahman · Dec 22, 2011

Forst of all, congrats on the purchase. This is a terrific camera system.

I regularly use a a 645 Pro TL, and have never had this problem. But I did have a tough time learning the right way to load the film onto the 120 insert. Presuming this is the first roll you've tried with this new camera, the only things I can think of:

1) Make sure you are loading the film onto the film insert correctly. Film loading is not very intuitive on these camera backs, and a diagram helps. Do you have the manual? PDF versions can be found online at no cost.
2) Maybe try another film insert &/or back? Perhaps the film is not being wound tightly, and that is what is throwing it off? After loading, you definitely want to make sure the film is wound tightly.

Good luck!

tkamiya · Dec 22, 2011

I had a Mamiya 645Super that exhibited a similar issue.

First, do your test on a tripod and shoot with a mirror locked up. The DOF of MF cameras are smaller than 35mm and it is often harder to focus accurately.

I did this and confirmed the focus was off a bit. It was off enough to cause issues using 150mm lens wide open. My problem was that little plastic part that keeps the mirror at exactly 45 degrees has cracked and mirror was resting askew. Focusing on SLR depends on lens-mirror-focus_screen and lens-film distance being exactly equal. Anything that will disturb this calibration will cause the focus error. I hear (I don't know for sure) the focus screen on M645 are adjustable. I didn't go this route because my body had more issue than just focus. I replaced mine.

With nothing to lose, I played around with mine. This is not a DIY adjustment. I messed up mine more than fixed it. (again, it was a lost cause body anyway)

SafetyBob · Dec 23, 2011

I have had my 645 Pro for good 3 years now and find that unless I spend the time to exactly focus I pretty much get soft focus to out of focus results. I recommend you plant it on a tripod and do some test shots at exact distances so see if it's you trying to focus on the go or if it's the camera. I may actually do this for myself with mirror up and down just to see what's going with mine. I tell you I believe it's me not being able to focus quickly enough as a 3 year old (and 14 year old) do their thing, but perhaps I too have a problem I am not aware of with the mirror.

I do love my 645 Pro, when I hit it right, the results are very much worth the wait. Let us know what your do and what you find. Very interested to see what you find....

Bob E.

keithwms · Dec 23, 2011

You can point your camera at a bright object (e.g. a lamp) and put some thin paper at the film plane and check registry. Make sure the GG is correctly oriented, I have seen them flipped around or weirdly modified in bodies that were used. The rough part should of course face into the camera body.

It is a great system, one of my favourites. But when you buy something used, you'd be surprised what the previous owner(s) did!

stavrosk · Dec 28, 2011

keithwms said:
put some thin paper at the film plane and check registry. Make sure the GG is correctly oriented

I am sorry but I cant say I understood what you proposed I do...

keithwms · Dec 28, 2011

If you open the film back and remove the insert, you can put some paper at the film plane and fire the shutter on bulb to check the registry. There should be no problem there; normally you do this only to check the shutter. That should be fine.

The GG could be in the wrong place though, make sure that the frosted side is pointed down, into the camera. I have seen them turned around.

stavrosk · Mar 9, 2012

I took a tape measure and so I set an object at exactly one meter distance from the film plane. Then I looked through the viewfinder and it looked sharp if I focused for a distance a little bit further away. Say 0.2 m more.
Then I did that with another lens and I had the same problem.
Therefore it is definitely not a lens problem.
Is there anyway I can fix it myself?

Roger Cole · Mar 9, 2012

keithwms said:
If you open the film back and remove the insert, you can put some paper at the film plane and fire the shutter on bulb to check the registry. There should be no problem there; normally you do this only to check the shutter. That should be fine.

The GG could be in the wrong place though, make sure that the frosted side is pointed down, into the camera. I have seen them turned around.

OP may not understand "GG."

GG = Ground Glass which on a MF (or other SLR) camera = "focusing screen."

IOW, make sure some bozo didn't put the focusing screen in backwards!

I just got a 645 Pro myself. Shot some film but not developed yet. Sure hope it doesn't have this issue - nice camera. Thought it might replace much of my use of my Yashicamat 124 AND my 35mm system, but I don't think it will. It's much bigger and heavier than either so I think will find its own niche for my use.

stavrosk · Mar 9, 2012

Roger Cole said:
OP may not understand "GG."
IOW, make sure some bozo didn't put the focusing screen in backwards!

Thank you so much for the help.
If you can tell me what is OP, where the focusing screen is and how do I know the right side it should be put then I will be very grateful!
Thank you

Roger Cole · Mar 9, 2012

stavrosk said:
Thank you so much for the help.
If you can tell me what is OP, where the focusing screen is and how do I know the right side it should be put then I will be very grateful!
Thank you

OP = Original Poster. I should have just scrolled up to get your user name.

The focusing screen is inside the camera body, above the mirror or below the prism or waist level finder. I have only had my 645 for a short time and have never had the AE prism finder off it, so I can't tell you too much about checking it yet. I'm sure someone else will give you more details. I know the right side and so on, and I'm sure I could get into mine and determine it, but I haven't done it yet and can't tell you exactly how.

stavrosk · Mar 9, 2012

Thank you very much for you reply!
I really apreciate it!

tkamiya · Mar 9, 2012

On M645Pro, there is no way to put the screen backwards - a little tab for handling works as an index. If you do put it backwards, it won't lock in place.

Having mucked around with my own, my advise is to send it in and get it adjusted - especially if you are expecting it to be spot-on when critically focused with wide open aperture.

I wish I kept my junker M645.... I'd send it to you so you can play. Unfortunately, I gave it away for someone who wanted to take it apart for parts.

eSPhotos · Mar 9, 2012

Sounds like the previous owner has adjusted focus screen to focus infrared ...
Yes, send it in to get it fixed.

danidoine · Dec 6, 2015

Hi
I'm new to the forum and although this is a really old threrad thought I would add that I think with the 645 Pros, the most common problem nowadays is the plastic part that the mirror rests on supported by a spring on the inside right of the camera (if you look into the camera after taking a lens off). This part is sadly weak (probably gets weaker over time) and is difficult to replace although nowadays it must be easy to 3D print a new one.
Apart from keeping the mirror aligned correctly when it is down I would expect that the part helps cushion the mirror on return and using a camera without this part functioning could cause more damage. So if you are thinking about getting a Mamiya and see that the part is missing, broken or even cracked, I would definitely recommend not buying it! Very few sellers ever show you the inside of the camera on ebay, but you can always ask.

I'm not sure whether to try to get a replacement for the one on mine which broke recently or just sell my Pro for spares (I also have a Super anyway which is still working fine). It's a shame because I love using Mamiyas more than any of my other equipment.

Regards,

Mamiya 645 PRO focus

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