Mamiya M645 shutter speeds are off

[cerber0s]

I finally got a Mamiya, the regular M645 (not 1000s). The price was right.

I’ve run two rolls through it and they came out ok. The slow shutter times, longer than 1 second (1 second is ok), are way off, about twice as long as they should be.

Yesterday I used a speedlight when shooting, and I have a consistent shadow band at the bottom of every frame (yes I used the correct flash sync speed), which has me thinking that either one of the curtains is lagging, or the flash sync needs to be adjusted.

Now, I can either send it off for service, or attempt the service myself. The interwebs claim that the shutter speeds can be adjusted via a potentiometer, and that it’s sometimes necessary to replace a couple of capacitors as well. The Mamiya M645 service manual says different though.

I’m leaning towards sending it for service, unless you guys have some good advice.

I really like the camera otherwise.

 

[Oldwino]

The biggest "problem" with getting these cameras serviced is that often the repair cost is the same (or more) than just finding a different body. The best part of a repair, though, is that your camera should be in tip-top form afterwards, and buying a second body...well, you are rolling the dice...

 

[chuckroast]

I finally got a Mamiya, the regular M645 (not 1000s). The price was right.

I’ve run two rolls through it and they came out ok. The slow shutter times, longer than 1 second (1 second is ok), are way off, about twice as long as they should be.

Yesterday I used a speedlight when shooting, and I have a consistent shadow band at the bottom of every frame (yes I used the correct flash sync speed), which has me thinking that either one of the curtains is lagging, or the flash sync needs to be adjusted.

Now, I can either send it off for service, or attempt the service myself. The interwebs claim that the shutter speeds can be adjusted via a potentiometer, and that it’s sometimes necessary to replace a couple of capacitors as well. The Mamiya M645 service manual says different though.

I’m leaning towards sending it for service, unless you guys have some good advice.

I really like the camera otherwise.

If you are in the US check with CameraWiz in VA or Dave Easterwood in MI. Both of them work on stuff like this and are reasonably priced.

 

[MattKing]

The slow shutter times, longer than 1 second (1 second is ok), are way off, about twice as long as they should be.

Are you saying that everything shorter than 1 second - 1/4, 1/2, ... 1/60, 1/125, 1/250 etc. are all fine?
If so, I would just live with it.
Anything longer than 1 second can be done reliably with a cable release and Bulb.

 

[cerber0s]

The biggest "problem" with getting these cameras serviced is that often the repair cost is the same (or more) than just finding a different body. The best part of a repair, though, is that your camera should be in tip-top form afterwards, and buying a second body...well, you are rolling the dice...

Yeah, that’s the thing. I rather spend the money on a service and know it’s good.

If you are in the US check with CameraWiz in VA or Dave Easterwood in MI. Both of them work on stuff like this and are reasonably priced.

I’m not, I’m in Sweden. The good thing is that wi still have two good camera techs here. One used to be an authorized Mamiya tech back in the day. Spare parts might still be an issue though.

 

[cerber0s]

Are you saying that everything shorter than 1 second - 1/4, 1/2, ... 1/60, 1/125, 1/250 etc. are all fine?
If so, I would just live with it.
Anything longer than 1 second can be done reliably with a cable release and Bulb.

That is what I’m saying. I changed my initial post after having done some more tests. At first I thought it was all of the times, but everything down to and including one second seem fine while 2-8 seconds are twice of what they should be. I think I can probably fix those by replacing a capacitor though.

The flash sync that’s out of whack is still a problem though.

 

[MattKing]

Did flash synch work with 1/30?

 

[cerber0s]

Did flash synch work with 1/30?

I never tried 1/30. I did accidentally try 1/125, and that was about twice as bad as 1/60. I did find a part in the service manual about adjusting the flash sync though, so it might be doable. There are no signs at all of any shutter drag when I don't use flash.

 

[MattKing]

1/125 should not work - so that is a good thing.
I would try 1/30 - if that works, it means the camera is at least usable, which may influence your decision.

 

[cerber0s]

1/125 should not work - so that is a good thing.
I would try 1/30 - if that works, it means the camera is at least usable, which may influence your decision.

I’ll try that too, but am all out of “cheap” film for now.

 

[OAPOli]

I agree that the timing issue is likely due to a faulty capacitor. There is a video on youtube showing the replacement.

I'm not sure about the flash sync but I believe you can test it without film. With the lens and insert out, go in the dark and fire the camera + flash while looking through the rear.