Mamiya RB67 problem
 

Hello!

I am new to film photography and developing. I am shooting black and white on my rb67 and when the rolls are developed there are two blank shots on each roll, in the middle of the roll. At first I assumed it was a one off mistake but I have no idea why I am consistently missing those two shots. Anyone have any ideas?

Thanks

Chris.

Hello and welcome to Fadu Chris. It sounds like something is sticking. It could be the lens aperture/shutter. And by the way, I presume you are aware of the correct procedure to remove and put your lens back on, which is that the camera should always be in the cocked position right?
And/or a sticking light baffle/mirror issue.

In any event, because many of these cameras were the workhorses of the professionals it's probably time for a service and it should give your RB a new lease of life.

Hi Chris,

Welcome to FADU, can't comment on your problem, but will say that I used to own an RB67.

Sold it to fund another purchase. A decision that I really regret, wish I had never sold it.

It's a great camera and well worth getting serviced.

Ian

have you tried another film back ..




www.essexcockney.com

When I get stray blank frames with my Mamiya RB67 it's because I've left the lens in the "mirror up" setting after doing some cable release actuated long exposure shots. Remembering to set the lens cable release socket back to N for ordinary work cures the problem.

Thanks for the replies everyone. I just had all the seals replaced so can't budget for a service right now, though I suspected that might be what was necessary. I haven't used the camera for long exposure so I dont think its a setting thing but I will double check before using it again that everything is set to what it should be. I assume it is something to do with the camera back? I noticed on my last film it also mangaged to do a double exposure so perhaps when I am winding the film on something mechanical is failing?

If you have a spare roll to sacrifice, it may be work running it through the camera a few times and seeing if you hear the shutter not firing (!?), or the mirror not flipping out the way - or if you suddenly feel yourself winding on further than expected in the middle of the rool.

When shooting for real, it is easy to miss the fact that you are having to wind on twice as much as usual or not notice that the mirror did not go KER-CLUNK!

Good luck, Bob.

There should be an inter-lock to prevent the film from being wound on without the shutter being fired (or at least there is on mine).

Chris, I would recommend you shoot a test roll of film at something boring (like a wall) and concentrate on using the camera - cock the shutter and wind the film on, then fire the beast - repeat 10 times.

Then develop the film and check that all the frames are exposed.

If they are all there, then you have somehow managed to over come the inter-lock somehow (?) and you need to concentrate on how you use and handle the camera.

If the problem remains, then load the camera again and look down the lens as the camera is fired (a slow shutter speed helps) - does the lens shutter always fire ?

If the shutter always fires - its probably the film curtain at the back of the body, isn't always getting out of the way.

The other thing to remember when using the camera is - are you pulling the film back darkslide out fully when you use the camera ?

It is perfectly possible to fire the camera with the darkslide pulled out only a very small amount - enough to allow the camera to operate but not enough to expose the film.

As a carry over from my LF camera, I always hold the darkslide in my left hand as I fire the shutter cable which is in my right hand.

I hope this helps

Martin

Martin and Bob, both excellent replies, thank you. I will test a roll as suggested and see what happens!

Correct me if I'm wrong, but didn't the early models of RB have no interlock between shutter and film wind? Chris, if your's is one of those, perhaps you've simply wound the film on one frame extra without exposing it? Easy mistake to make -- I should know, as I do it all the time on my old folding cameras (red window winding). :rolleyes:

Otherwise, as Martin suggests, there may be something wrong with the shutter not fully cocking or simply not firing occasionally. I have a Mamiya C330, and with the 80mm lens the shutter cocking lever on camera body doesn't fully cock the shutter lever on the lens -- it stays in what looks like the cocked position, but doesn't fire. Easy work-around on the C330, as I manually move the lens lever the last couple of millimetres to the fully cocked position. Hard to tell if this is happening in the RB, though, as it's all internal. Is there any play or slop in the bayonet mount, camera cocking lever or lens lever?

Good luck fixing it!

Svend