shooting 120 from the wrong end on rb67?

nwilkins · Nov 8, 2012

I was having a friend help load one of my rb67 backs and somehow he managed to wind the entire roll of film over to the take up spool. the back was definitely closed so i dont know how this happened. In any case, now the film is at the "exposed" stage without ever having seen any light. does anyone know if it is possible to move the roll back over to the left side and shoot it starting from the "exposed" end? Or is there any other way to salvage the roll?

Thanks!

summicron1 · Nov 8, 2012

get thee a dark bag or a darkroom, take the film out of the back and IN TOTAL DARKNESS hook the paper backing back onto an empty spool and just start winding it up .

Be careful for when the end of the film comes along because it is not taped down to the paper on that end, when you reach/feel it just make sure it stays in the roll. When you get to the other end of the film, where it is taped down, there may be a bump if it is pushing against the tape there but that's not a big deal.

keep winding until you get to the end, turn on the lights, reload and shoot.

tkamiya · Nov 8, 2012

I'm NOT quite sure what happened. If you are sure the film never saw the light, you could take the back into a darkroom, rewind it and load it the right way. There IS a chance the emulsion surface may have been scratched though. If it were my film, I won't use it for anything important.

ic-racer · Nov 8, 2012

When you get to the tape, carefully remove it, take up the slack and re-affix it.

Chris Nielsen · Nov 9, 2012

I find that with one of my backs if I don't have the darkslide in when I start advancing the film, it doesn't lock at 1 and simply continues until the roll is gone.

Ric Trexell · Nov 10, 2012

Didn't he stop at the start line?

I was trying to figure out what your friend did, and why he would wind all the film to the end. When you put a roll in, you line up the start arrow or line or whatever you film says, with an arrow on the insert. Then you close the door and wind it a few winds before it should stop. If it doesn't stop shortly, something is wrong. I would think generally about two winds of the lever should do the trick, and if it doesn't you should know something is wrong.

The only thing I can think of, and I did this stupid mistake myself once, was to run the film directly from one roll to the other without going in front of the pressure plate. As if it was 35mm film. I caught it right away. (I'm not supposed to do that sort of thing for another 20 years.) Could that have been what he did? Ric.

Chris Nielsen · Nov 11, 2012

When I got the rb I had previously used a tlr and tried loading it the same way, which meant I ran the film between the spools without going around the other side of the back over the pressure plate. Doesn't work very well though.

nwilkins · Nov 13, 2012

thanks for the replies everyone. When I say I'm not sure what happened, here is what I mean:

I loaded the film the same way as I always do - correct routing, stopping with the arrow in the right place, closed up the back as normal. then I gave it to my friend to wind as I started loading a second back. I said "just wind it until it stops". normally of course it is only about 4 or so winds and then it stops automatically at the first frame. However I wasn't paying attention and he didn't know any better and for some reason the back did not automatically stop the film, so he rolled it all onto the take up spool. Bascially the back seemed not to recognize that a film had been loaded. It was a weird glitch since I loaded another roll in the back and it worked just fine.

nwilkins · Feb 18, 2013

Yesterday this finally happened again (this time I was winding the film) - I loaded the back correctly and closed it up but when I wound the film the counter did not catch. I wound it a second time to make sure it wasn't working, then opened up the back, closed it again and it worked as normal (now though I suppose I might not get 10 shots?). Does anyone know why this might be occurring? Exactly how does the back know there is film in it to start the counter moving? If I knew what was supposed to be happening mechanically I could see if it is something easy to fix.

nwilkins said:
thanks for the replies everyone. When I say I'm not sure what happened, here is what I mean:

I loaded the film the same way as I always do - correct routing, stopping with the arrow in the right place, closed up the back as normal. then I gave it to my friend to wind as I started loading a second back. I said "just wind it until it stops". normally of course it is only about 4 or so winds and then it stops automatically at the first frame. However I wasn't paying attention and he didn't know any better and for some reason the back did not automatically stop the film, so he rolled it all onto the take up spool. Bascially the back seemed not to recognize that a film had been loaded. It was a weird glitch since I loaded another roll in the back and it worked just fine.

polyglot · Feb 18, 2013

I think the backs detect the presence of film because the little nubs that hold the spools are both pressed-in slightly. I haven't tested that by putting a couple empty spools in there though.

However, I think your problem is that the back-closed detection is failing. The counter only winds on when the back is closed and you can crank it all day to no effect while open.

nwilkins · Feb 18, 2013

okay next time the back is empty I will look into this - any idea how/where the back closed detection occurs?

paul ron · Feb 18, 2013

Sure it never stopped it was loaded from roll to spool n never went over the end roller that detects n advances the counter works to meter the frames.

nwilkins · Feb 18, 2013

paul ron said:
Sure it never stopped it was loaded from roll to spool n never went over the end roller that detects n advances the counter works to meter the frames.

sorry I don't understand what you are saying. Can you clarify? The film was loaded correctly, if that's what you're wondering?

polyglot · Feb 18, 2013

nwilkins said:
okay next time the back is empty I will look into this - any idea how/where the back closed detection occurs?

I would suspect the mechanism is in the latch that holds the back cover closed.

Jeff Kubach · Feb 18, 2013

Maybe you loaded from the back end instead of the front end.

Jeff

paul ron · Feb 19, 2013

nwilkins said:
thanks for the replies everyone. When I say I'm not sure what happened, here is what I mean:

I loaded the film the same way as I always do - correct routing, stopping with the arrow in the right place, closed up the back as normal. then I gave it to my friend to wind as I started loading a second back. I said "just wind it until it stops". normally of course it is only about 4 or so winds and then it stops automatically at the first frame. However I wasn't paying attention and he didn't know any better and for some reason the back did not automatically stop the film, so he rolled it all onto the take up spool. Bascially the back seemed not to recognize that a film had been loaded. It was a weird glitch since I loaded another roll in the back and it worked just fine.

The film in a normal load passes over an end roller. That roller detects the film and meters the frames as it counts.

If the film is not making good contact with this roller or there is an adjsutment out of spec dealing with this roller... it will wind on forever nonstop.. as well as some other intermittant inconsistancies... like you say it has a symptom with the dark slide.

As also mentioned by others.. there is a small tab that gets pushed in when the door is closed, that engages the counting mechanism and roller sytem. If the tab is not properly pushed in or the mechanism is out of spec it too will give you similar symptoms... but still part of trhe same roller mechanism linked by a signal arm; that is the most comon part to go out of adjustment..

But it all starts as you described above.. all weird quirky symptoms... asking for service.. not screaming yet. Perhaps the service costs too much these days... so buy a backup for $25 before this one drops dead on you.. cheaper solution?

.

paul ron · Feb 19, 2013

nwilkins said:
okay next time the back is empty I will look into this - any idea how/where the back closed detection occurs?

Look at the door edge up by the counter.

nwilkins · Feb 19, 2013

okay thanks everyone. The problem must be with the back closing mechanism, since as I said I opened the back after two winds, then re closed it (not altering anything) and then it worked just fine.

polyglot · Feb 19, 2013

paul ron said:
Look at the door edge up by the counter.

I just checked my RZ backs, and there's a little lever there on the top edge near the counter.

nwilkins · Feb 19, 2013

thanks!

shooting 120 from the wrong end on rb67?

Privacy & Transparency

Privacy & Transparency