Problem with Mamiya RB 67 Back

Well, I just took my RB67 ProS on its first outing and developed the film. Unfortunately, there appears to be a problem with the back. I shot three rolls and each seems to have a problem with the starting point of the roll. On one of them, the first image is kind of close to the beginning of the film, but usable. Another roll has the first shot overlapping the tape at the bigging just a little. The other roll has only eight images with the first one half off the front end of the roll and a very large amount of blank film at the end.

The only idea I have is to replace or fix the back. Does anyone else have an idea of something I could check or something that I might be missing that would cause this problem? I read the manual that Mamiya has on their site and think I loaded it correctly, but I am not entirely sure that I didn't miss something important. I do know that I wound the film to the start arrow for each roll.

Thanks!

Sounds like a film advance problem. It should take one and half draws of the film lever to the next frame. Check to see if the advance lever is set to single or multiple exposer. Thats the smaller switch under the film lever. The red dot I believe indicates single or multiple exposures. My RB does the same loading/advance problem. But, I worked it through.
I don't think you should go and get another back unless you want to.

Robert8x10 said:

Sounds like a film advance problem. It should take one and half draws of the film lever to the next frame. Check to see if the advance lever is set to single or multiple exposer. Thats the smaller switch under the film lever. The red dot I believe indicates single or multiple exposures. My RB does the same loading/advance problem. But, I worked it through.
I don't think you should go and get another back unless you want to.

Click to expand...

The multiple exposure lever is off, I did check that. How did you work the problem through? All of the frames were perfectly spaced, it was the placement of the first frame that was problematic. It seems that sometimes the back doesn't want to advance far enough from loading until the first frame.

Robert8x10 said:

Sounds like a film advance problem. It should take one and half draws of the film lever to the next frame.

Click to expand...

I only have one draw with the film advance lever to the next frame with my RB, never had any issues----10 frames evenly spaced.

I spoiled a couple of rolls of film to try to test the back and have had no problems at all. I rerolled the film over and over, probably loading the back 20 times without incident. I guess I will need to see what happens the next time I use the camera for real.

Thanks!

Paul-

Just checking...did you align the starting line on the film with the starting mark on the back? If not, that would cause problems like you're describing. It's such a simple thing that it's possible to forget it.

As to the roll with eight images: Do you remember shooting 10 or did you only get 8 when you shot it?

Be well.
Dave

That would have been my guess as well, but I am more than certain that I did. Also, it doesn't wind on that far to get to the start arrow, so if I had missed it but had wound it enough for the film to have held, I don't think that I could have lost more than about a shot, or maybe even less. On the roll where I only got eight (seven and a half, actually) it shot all ten, but the first two and a half came before the film began. There are two shots that I remember taking that are completely gone.

I have come up with another idea, perhaps I didn't get it on the takeup reel well enough and it slipped at some point. It could have eventually gotten tight enough to start pulling again and from then on it was working correctly. One thing I did notice when playing around with it last night was that there is a noticible hang when the beginning of the film rounds the corner to the focal plane. I do wonder now if it got hung there and once the paper was tight enough on the take up reel, started moving again.

I guess I am going to have to just see if this behavior comes back.

Thanks!

Paul.

If you think the takeup reel isn't holding well enough, see if you can find a Fuji reel to install as the takeup reel. (These are the ones with the "bumps" inside of the slot.) They seem to hold film better than any other reels...might be worth a shot.

Good luck.
Dave