Mamiya RZ67 - Light Leak?

I own a Mamiya RZ67 and I believe the back is experiencing a light leak (see attached).

The thing that is making me unsure however is the fact that the leak is really random. On a typical roll of film it is happening to two, perhaps three frames. It never happens on the same two or three frames on the roll. In most cases, I can take the same exact shot, same framing, same exposure, the camera doesn't move on the tripod, and one frame will have the leak and the very next frame, taken under the exact same conditions, will not.

Is it possible for a light leak to be random like that?

arealitystudios said:

I own a Mamiya RZ67 and I believe the back is experiencing a light leak (see attached).

The thing that is making me unsure however is the fact that the leak is really random. On a typical roll of film it is happening to two, perhaps three frames. It never happens on the same two or three frames on the roll. In most cases, I can take the same exact shot, same framing, same exposure, the camera doesn't move on the tripod, and one frame will have the leak and the very next frame, taken under the exact same conditions, will not.

Is it possible for a light leak to be random like that?

Click to expand...

The original RZ67 film backs had foam light seals. They redesigned the backs with the Pro ll to not need this material. Check the foam to see if it is gummy. You may need to replace the seal material.

Yes, light leaks may be intermittent at first until they get worse. From one shot to the next the fit-up between the back and the camera can change slightly do to operating the camera.

It could be the back hinge area and the unwanted exposure occurs when the film has been in position for a long period of time, frame not advanced, and the position of the light source.

Alan Gales said:

The original RZ67 film backs had foam light seals. They redesigned the backs with the Pro ll to not need this material. Check the foam to see if it is gummy. You may need to replace the seal material.

Yes, light leaks may be intermittent at first until they get worse. From one shot to the next the fit-up between the back and the camera can change slightly do to operating the camera.

Click to expand...

I believe mine is the newer version, the one with the film counter on both sides of the back so you can read it when it is rotated. I've read in a few places that those use a light trap instead of foam seals.

If the issue is the hinge as another poster suggested, is that repairable do you think?

Looking at page 6 of this manual, http://www.cameramanuals.org/mamiya_pdf/mamiya_rz67_pro_ii_d.pdf, the hinge and latch areas use a baffle system for light seals.
With the film holder off the camera remove the insert from the outer shell. With the outer shell open check the hinge for play in any direction, it should be less than .001 inch. Next close the shell and inspect the light baffles for any gaps and check the latch for a secure lock. Reattach the film holder with insert installed, lock the mirror up and shine a bright light in through the lens opening or lens in total darkness while observing the film holder. Shine the light through the viewer opening and check the film plane for a hint of light.

An even exposure like yours is most likely the hinge as the alignment in frame is the same. A darkslide slot is rarely even when they leak and the latch would appear at different positions in the frame from frame 1 to frame 12.

The hinge pin could be worn and may be replaceable. A sprung hinge from the back swinging open should be repairable by pushing the hinge back into position.

arealitystudios said:

I believe mine is the newer version, the one with the film counter on both sides of the back so you can read it when it is rotated. I've read in a few places that those use a light trap instead of foam seals.

If the issue is the hinge as another poster suggested, is that repairable do you think?

Click to expand...

The newer Pro ll backs say Professional ll on them. Scroll down and you will see it: Dead Link Removed

Mamiya has changed their website and does not include any film items anymore. I couldn't even fine a phone # for you to ask about service. If the hinge is worn out it may be cheaper to just buy another used back.

If you do decide to buy an additional back or two I would buy the Pro ll backs. I feel they are worth the extra money. I used to own an RZ with one original back and two additional Pro ll backs that I bought.

just to cover all the bases, I have had flare that looked like a light leak as a result of not being careful when putting the dark slide back in. if you rush and it bends a little it can reflect light onto the film. I doubt that is what is happening here but something to think about, just in case.

nwilkins said:

just to cover all the bases, I have had flare that looked like a light leak as a result of not being careful when putting the dark slide back in. if you rush and it bends a little it can reflect light onto the film. I doubt that is what is happening here but something to think about, just in case.

Click to expand...

This actually looks exactly like what my RB67 does when I'm not careful with the dark slide. I'd wager half a donut that it's a darkslide issue.

I've had an issue with an original back where the shell bowed over the insert. Not sure this is the same issue though.