Mamiya RB67 pro sd revolving back/shutter release

[icepack]

Hi! Finally found an active photography forum.
I'm new to film and just got the last parts of my Mamiya RB67 ProSD in the mail.
I've searched and searched for somebody with a similar problem, can't find it.

Sorry if you've all seen this 100 times.

Without the revolving back and 120 film back, the shutter and mirror work fine.

when i attach the back piece and lock the revolving back into place, advance film,i can't get the shutter to release. i can see the back right pin move into the film back when i press the shutter.

with the dark slide in, that pin doesn't come out. the film is advanced, i've tried every combination of the multiple exposure level, etc.

i know i just wasted a roll of film, i'm willing to lose another to learn how to use this.

is there a step i'm missing that's not letting the shutter release?

note: when i twist the revolving film back and get half way from horizontal to vertical(45 degrees), the shutter will release when i press it(the film come out as exposed). but once it's all the way back in place, shutter won't release.

any help for an eager photographer newbie?

 

[Steve Smith]

I assume you have the dark slide out and you know that you have to both advance the film and cock the shutter (two levers) to get the camera ready to fire the shutter.

Does the shutter fire if the back is switched to multiple exposure?



steve.

 

[xtolsniffer]

That does sound a bit odd. If the rotating back is half-way round at 45 degrees, the shutter shouldn't release, it should only release when it's locked in place at either 0 degrees or 90 degrees. Is the back from an RB ProDS as well rather than an earlier back? You can tell if there is somewhere to store the dark slide in a slot at the back of it.

 

[xtolsniffer]

By the way, you don't need to waste film in checking this. 1. Don't put a film in the back.
2. Move the multiple exposure lever on the back forward so that the red dot shows (I'm explaining this from memory so I hope it corresponds!).
3. Make sure the rotating back and the film back are at the 0 degrees position, there should be a nice 'clunk' sound when the back is at the right angle.
4. Make sure there is a lens on the camera.
5. Remove the dark slide.
6. Cock the shutter.
7. With no film in the back, winding the film on makes no difference.
8. Set the lens to any shutter speed in the 1-1/400th second range.
9. Make sure the shutter lock collar around the shutter button is rotated so that the shutter is free to be depressed.
10. push the shutter button.
This should make the shutter fire.
If this doesn't work there may be an issue with the film back. You mention that you have got the last parts for you kit, did you get them all from different palces? All types of film backs (Pro, Pro S and Pro SD) will work on all RB variant cameras. The limitation is that Pro backs do not have the multiple exposure prevention mechanism so if you use them on a ProS or ProSD camera you have to remember to wind on the film. The rotating back adaptor (the bit that sits between the camera and the film back) from the Pro are not compatible with ProS and ProSD cameras. I don't know what the effect of using an adaptor from the Pro is on the Pro S and Pro SD actually is, since I haven't tried it, but if you got your bits from different places, that migth cause this effect.

 

[Christopher Walrath]

I got mine with two film backs, a regular back and a ProS back. The shutter wouldn't fire with the Pro back because the tab behind the shutter stud wouldn't retract into the back. So after looking and fiddling and figuring for about an hour I just decided to make it work. I took that little tab and bent it out of the way to give the stud enough clearance to allow the shutter to fire. I wouldn't recommend just doing this but sometimes a simple little adjustment is all you need. Just don't break anything doing it.

 

[David Brown]

http://www.mamiya.com/assets/pdfs/6x7/RB67_Pro-S_v7.pdf

 

[icepack]

thanks everybody so far for your replies.

The film back is a 120 Pro S

xtolsmith:
the revolving back came with the camera with is a Pro SD. it appears to have a pin for every hole(people mentioned the pro backs don't have certain pins).
i followed the steps you posted and still, the shutter doesn't fire.

steve smith:
the shutter has never fired unless the revolving back is at 45 degrees.

at 45 degrees, this pin pops up when i press the shutter:
Dead Link Removed

if i put my finger over that pin to stop it from moving(when the back is at 45 degrees), the shutter does not fire. which makes me think it's got something to do with that pin



EDIT:
finally got it.
when i bought the proSD back, the seller on ebay said that the shutter button can be sticky. i think this was the problem. i've got it firing now, i just have to press the shutter button firmly 1 or 2 times.

thanks again everybody!

 

[paul ron]

Nothing on the RB should require force to get it to work. If the fire button is sticky, it needs attention since internal parts probably need lube ot parts replaced. Forcing anything on an RB causes internal damage and will eventually cost you dearly. Your camera needs to be serviced.

Does the camera function properly without the rev back?

From what you are saying about the rev back in the off position solving the problem, the pins at the corners may be bent or in need of lube. But that wouldn't allow you to fire it since there are interlocks that should kick in. So that also says the interlocks need to be examined.

 

[John Koehrer]

What Paul said about force.
The pin you're seeing goes into the post that you can also see in your picture, If the pin in there is binding it won't release the interlock.
Regarding the force on the release button, does it stick like from a sticky substance or is it more mechanical? I would try just a drop or two of alcohol on the button and if it frees up follow it with a drop of liquid lighter fluid such as ronsonol. It will evaporate quickly & leave a barely perceptible deposit of lube.

 

[paul ron]

Ya know, you may be onto something here, like maybe foreign gunk like maybe a soda spill. If it is sticky as in old grease, you can access the fire button by taking off the bottom plate n take a look see in there. But it shouldn't be lubed to begin with.

The cock n release catch is actually in the left side panel, not the lever side. When you cock it there is a hook that engages. When you fire it, the hook is released and everything happens like clock work. One thing triggers another and another. Each part of these trigers have an interlock so if all conditions aren't met, it won't fire. THere is very little lube on any of these parts since they are self lube delrin bearings n rollers.

Now a forced camera will have damaged delrin rollers n bearings, and/or bent levers, which causes an out of alignment condition which holds up interlocks from clearing properly which in turn causes weird n intermittant firing conditions.

So if you have to force the fire button, more than likely something is bent or damaged. But a tiny drop of WD on the fire button and the pins in the rev back is not a bad idea and won't hurt anything. The pins in the rev back should move freely, check em to see if they are bent? It's very common to lay the camera down on it;'s rev back with no film back on it and bend these pins or get dirt in em.

.

 

[BrianShaw]

But a tiny drop of WD on the fire button and the pins in the rev back is not a bad idea and won't hurt anything.

Please don't do this if you think "WD" means WD-40. WD-40 has no place in camera work other than for removing sticker gum from the surface of leatherette covering. Consider another lubricant... like sewing machine oil, gun oil, or even 3-in-1 oil and carefully heed the good part of this advise: "tiny drop".

 

[Ross Chambers]

I thought that I knew my RB backwards until yesterday. I couldn't fire the mirror up mode, nor the single hit mode with all the safety things checked. Eventually I spotted that the back was rotated about 2 degrees off square. I was pleased to escape with one dud exposure and the 2 rolls I exposed thereafter offered no problem.

Mr Mamiya really did have a thing about double exposure!

Regards - Ross