Mamiya RB67 Pro S and shuttter locking mechanisms

[jusjee]

Hi,

I'm new to this site, but have found a lot of useful information here. Unfortunately, I have not been able to find the issue (if it is an issue at all) that I have encountered. Hopefully someone here can shed some light.

First, I'll start off with my equipment:
-Mamiya RB 67 Pro S body
-Mamiya Pro SD 6x4.5 back/Pro SD rotating adapter
-90mm KL lens

Most of the issues I've seen with shutter locking deal with people not able to fire their shutters, mine is sort of the opposite. Keep in mind that I am very new to this camera as I just bought it used a couple days ago, but it seems that the shutter should not fire when:

-there is no film loaded
-the dark slide is in place
-the multi exposure setting is off (no red dot)

However, I am able to fire the shutter. I have not loaded film as I bought this system without a finder and I am awaiting the finder in the mail now, but from everything I've read (the manual, forums, other websites), with the above configuration, I should not be able to fire the shutter. Am I incorrect in this assumption? I'm thinking the cause of this is either two things:

-a minor loss of functionality when using the Pro SD adapter/back and KL lens with the Pro S body
-this capability is just broken

Hopefully someone on here can answer this. Thanks in advance!

 

[markbarendt]

Good morning and welcome to APUG.

You are correct, with the dark slide all the way in, the shutter should not fire. You should need to pull it out far enough to get clear of the interlock. The little open triangle in the dark slide should need to be visible before it allows the shutter to fire.

As long as that's the only problem, you will just need to remember to pull the slide before you shoot.

 

[markbarendt]

BTW, if you fall in love with the RB system, just be a bit patient and keep looking at places like KEH, local camera clubs, and on EBay.

I picked up a fully functional "bargain" body only last month for ~$45. They had another for $60 at the same time. These deals come and go.

 

[mickster]

Your assumption is correct; the camera should not fire either with the darkside fully in OR with the multi exposure switch on non-multi & no film in the back. Normally either one of these conditions would stop the shutter being fired.

My guess is that your symptoms are caused by the reolving adapter. This adapter controls the various interlocks in question. It could be some stuck pins on the adapter, or it could be to do with using a ProSD revolving adapter on a ProS body. The problem is not down to the KL lens. Check the various pins on the adapter - these are spring loaded and should be able to be pushed from the body side of the adapter. Lube any sticking pins with a tiny amount of lightweight oil and give it another try.

 

[hpulley]

I don't think the camera knows if there is film in the back or not. All it knows is whether the darkslide is in place and whether the back has been wound since the shutter was last fired.

If the dark slide is in place then it should not fire AT ALL no matter whether there is film in place, if the back is wound or if the multiexposure switch is on. With the dark slide in place it should not fire. If it does, this means the pins which normally prevent this are stuck or broken off.

Another thing to try, can you remove the film back if the dark slide is removed? The other side of the dark slide interlock is that it shouldn't let you remove the back while the slide is out.

What I wish is that there was an interlock on opening the back itself! There isn't, not on the Pro S backs anyways and I ruined a few shots when the release slide caught on my jacket/scarf recently...

 

[CGW]

A possibility. Is the ME feature actually working properly? The little lever may be moving but is it opening and closing the tab covering the little hole just in front of it? If there's nothing blocking hole when you shift the lever back to cover the red dot, then it's stuck in ME mode.

 

[jusjee]

Wow, I hate asking questions until I know I've tried my hardest to find the answer on my own, but you guys make it so easy to want to just ask here first.

Check the various pins on the adapter - these are spring loaded and should be able to be pushed from the body side of the adapter. Lube any sticking pins with a tiny amount of lightweight oil and give it another try.

I'd like to test this out, but am not sure Which pins would work the shutter locking mechanism.

Another thing to try, can you remove the film back if the dark slide is removed? The other side of the dark slide interlock is that it shouldn't let you remove the back while the slide is out.

With the dark slide out, I cannot remove the back.

Is the ME feature actually working properly?

Still not sure, but the hole that you mention is getting covered when I move the lever.

Thanks for the great responses. If anything, do you think this will affect my ability to take pictures with this setup?

BTW, if you fall in love with the RB system, just be a bit patient and keep looking at places like KEH, local camera clubs, and on EBay.

I picked up a fully functional "bargain" body only last month for ~$45. They had another for $60 at the same time. These deals come and go.

I'm trying this rig because I found a pretty good deal on Craigslist. I wanted to go with a Hasselblad because they are smaller and I prefer the 6x6 format (the only other medium format camera I have is a Rolleicord IV, but I don't want to be limited to the fixed lens). I figured I'll give this a try since the price was right and Mamiya makes the other camera that I lust for (Mamiya 6).

 

[MattKing]

Are you totally confident that the back is a Pro-SD back? I ask, because at least part of the behaviour you describe is what you would get if it was a Pro back (not Pro-S and not Pro-SD).

 

[CGW]

Struck me as possible but I assumed the OP could read the RB adapter and back. Maybe?

 

[hpulley]

As long as you remember to remove the darkslide and wind after every shot it shouldn't matter. You can get blank frames and double exposures if you aren't careful.

 

[jusjee]

Are you totally confident that the back is a Pro-SD back? I ask, because at least part of the behaviour you describe is what you would get if it was a Pro back (not Pro-S and not Pro-SD).

Yes, both the film back and the adapter have the Pro SD badge on them. The film back looks liek it may be an older SD back because most of the pictures I see look different. Mine looks more like a Pro S back, but with the SD badge. It also has a slot to put the dark slide in so that indicates to me that it is the SD version.

As long as you remember to remove the darkslide and wind after every shot it shouldn't matter. You can get blank frames and double exposures if you aren't careful.

That's what I'm hoping If that's the only thing wrong with the system, I'm fine with that, but it does irk me a little bit just because my personality likes to get to the bottom of these sorts of issues.

 

[jusjee]

Another thing that is weird about this (maybe due to it being a 645 back?) is the vertical and horizontal indicators on the adapter don't seem to match up with the "H" and "V" on the back. Is this normal? If not, could this be the cause? I've checked it out and there seems to be no other way that the back can attach to the adapter.

Thanks again for all of your help!

 

[johnnywalker]

I assume you know that the "normal" horizontal for a 6x7 back is actually vertical for 6x4.5. The 6x4.5 should come with a viewfinder template that corrects the image in the viewfinder. If you mean something else, I'm mystified!