Mamiya RB67 - new (old) back won't advance film unless film wind-stop release lever is moved to left

[peterB1966]

Dunno if there is something wrong with the back, hope to goodness not. This is my first roll with it, and though the film was advanced to 1 and the shutter was cocked, it would not fire.

Eventually I used the multiple exposure option to fire it, but then I couldn't advance the film.

So then I had to use the film wind-stop release lever (see red arrow on image to confirm which lever I am talking about) to allow the film to advance, after which I was able to fire the shutter in the usual way. Ditto for the next exposure, at which stage I stopped.

I have managed to find a discussion around this in 2004 on this forum, but it was inconclusive, so I thought I would see if anyone had any insight?

 

[M Carter]

The purpose of the "film-wind stop release" lever, far as I know, is to allow you to roll-off an unfinished roll of film without having to fire the shutter for each frame. If you use 120 film in a 220 back, it's a faster way to wind-off the backing paper since the back thinks you still have ten frames to go. The usual position of the lever is to the right (as shown in your pic), and it's spring loaded - you have to hold it to the left for it to disengage the winding from the shutter/cocking mechanisms. It basically unlocks the film-winding lever so it's independent of the camera body.

Beyond that, I don't know - the RB operates with linkages and pins that come from the camera body and through the revolving adapter, and if those get bent or stuck you can have problems, usually problems with the camera's safeties not letting you fire the shutter. You might send a message to MamiyaRepair.com, that guy is 100% legit.

 

[Neil Grant]

..there are 3 types of RB 67 camera and 120 backs. It's kind of important to know which you have as they are interchangeable though the way they function together may vary.

 

[Alan Edward Klein]

How do you know the shutter fired? What was the setting on the lens? (Keep in mind that the shutters are in the lenses.) When you release the big button on the bottom right, the mirror retracts but the shutter in the lens only trips if the lens knob is set on N for Normal on the lens. If the knob on the lens is set to M, (Manual) the shutter won't trip unless you release it with a cable release or you switch the knob back to N..

 

[Maris]

Check if the red indicator mark appears in the exposure counter window of the film back when the shutter is released.
If that red mark does not appear the linkage between the camera body and the film back is faulty.
In effect the film back "thinks" that the shutter has not been released and the double exposure prevention interlock will prevent the film from being wound on.
This interlock can be defeated by moving the multiple exposure lever forward and uncovering a red warning dot.
The interlock can also be defeated by pushing the film wind-stop release lever to the left.

The underlying problem is that the moving pin system that connects back and body and signals exposure is jammed
or maybe the revolving adapter and/or the film back are slightly out of alignment.

 

[MattKing]

The interlocks in the system are marvelous, but they do require reasonably regular service.
That rotating back is both great, and complex.

 

[peterB1966]

Thanks for all the responses.

First of all to respond to some of them:
this is a pro S 120 back for a pro S model.
Yes, I know the lever is for winding off the remaining film when it is not finished - hence my needing to use it can be seen as a symptom indicating a problem elsewhere.
The lens is firing on 'normal' - on this particular K/L lens the only way of getting the lens into 'manual' mode is to screw the cable release into the socket tightly enough, i.e. there is no switch.

I think in the end Maris' input is getting closer to the issue... I tried a shot, which wouldn't fire until I went into multiple exposure mode, and then it wouldn't wind once more.
This time, instead of using the wind-stop lever to advance the film, I removed the back and firmly re-attached it, and was able to advance the film in the normal way. Now to find something else to do a test shot on!

 

[villagephotog]

The purpose of the "film-wind stop release" lever, far as I know, is to allow you to roll-off an unfinished roll of film without having to fire the shutter for each frame.

Yes, I know the lever is for winding off the remaining film when it is not finished

Not that it matters here, but just for interest's sake, there is a second, equally important use for the film-wind stop release. On cameras that cannot signal to the back when an exposure has been made, that release is required to wind on to the next frame. This includes all Mamiya Press cameras, some of which can use the RB's Graflok-style backs. Those backs would not be compatible with the Mamiya Press system without the film-wind stop release.

On a Mamiya Press camera, releasing the film-wind stop is a necessary step in each exposure, and so all the rollfilm backs that camera can use (type M and type G) have those release levers. The sequence is: 1. release the stop 2. advance (wind) to the next frame 3. cock the shutter on the lens 4. press the shutter release. That's right; you need to operate four, count 'em four, separate buttons/levers for each shot. You fancy-schmantzy folks with your automatic stop release don't know how good you've had it. And those of you using cameras that a) release the wind stop and b) cock the shutter SIMULTANEOUSLY! when you advance the frame, well, you're living like kings.

I haven't been using my Mamiya Universal much lately, but I have it configured to use Graflok backs, and I have both an RB Pro S 6x7 back and an RB 6x8 back for it. I use that film stop release lever for every exposure (after frame 1, of course).

 

[MattKing]

IIRC, the procedure described by villagephotog is also required if you use the original RB67-Pro with any version of the RB67 backs. Compatibility with that model is the main reason for that lever on that back.
One of the interlocks in your camera/back needs service. It could be as simple as cleaning, lubricating and adjusting it .

 

[peterB1966]

Not that it matters here, but just for interest's sake, there is a second, equally important use for the film-wind stop release. On cameras that cannot signal to the back when an exposure has been made, that release is required to wind on to the next frame. This includes all Mamiya Press cameras, some of which can use the RB's Graflok-style backs. Those backs would not be compatible with the Mamiya Press system without the film-wind stop release.

On a Mamiya Press camera, releasing the film-wind stop is a necessary step in each exposure, and so all the rollfilm backs that camera can use (type M and type G) have those release levers. The sequence is: 1. release the stop 2. advance (wind) to the next frame 3. cock the shutter on the lens 4. press the shutter release. That's right; you need to operate four, count 'em four, separate buttons/levers for each shot. You fancy-schmantzy folks with your automatic stop release don't know how good you've had it. And those of you using cameras that a) release the wind stop and b) cock the shutter SIMULTANEOUSLY! when you advance the frame, well, you're living like kings.

I haven't been using my Mamiya Universal much lately, but I have it configured to use Graflok backs, and I have both an RB Pro S 6x7 back and an RB 6x8 back for it. I use that film stop release lever for every exposure (after frame 1, of course).

Most amusing!

 

[peterB1966]

IIRC, the procedure described by villagephotog is also required if you use the original RB67-Pro with any version of the RB67 backs. Compatibility with that model is the main reason for that lever on that back.
One of the interlocks in your camera/back needs service. It could be as simple as cleaning, lubricating and adjusting it .

Yes... it's what I suspected, in the end. Will see what I can work out before the additional expense of taking it somewhere...

 

[peterB1966]

Just an update, in case this helps anyone else: it seems the main culprit was the little fellow in the middle on the left third in the accompanying photo of the camera-side of my film back... it's a little metal panel that slides out when you advance your film, covering a hole underneath. This prevents a little rod inside one of the registration pins from going as far as it wishes to, hence letting the camera know the film is advanced and that you can shoot.

Once I worked this out, it was a simple step to realise all I needed to do was jiggle/tap the film advance lever to bring it out, and when that happened the little red flag would appear by my exposure number.