Removing stuck lens from RB67 Pro-S

DaveInAZ · Jul 14, 2021

Hi,

I am new to using this camera, so I'm in the love/hate phase. I love it when it works as expected, based on having read the manual many times. I hate it when it doesn't, which is all too often. I'm sure that a lot of the failure is my fault, but I'm not sure this one is my fault.

Last week I stuck my 65mm C lens on it, took some shots (I hope! Now I'm wondering if the shutter was actually stuck all along and it was just the mirror flip-flapping that I heard. I'll find out when I get the film developed.) and then tried to swap it for another lens. Nothing doing. That bayonet ring will not budge.

Looking online for a solution, I read about the "hold the shutter release in and push the cocking lever forward while twisting the bayonet ring" method. Tried it, but I can't move the lever once the shutter is released until I let go of the release button.

I read about the "stick a paper clip into the hole" method. I made the hole in the leather(?) and poked and prodded with various bits of metal at various angles and amounts of force applied, all to no avail. At no time did I feel like I was making contact with anything movable.

I make no claims to being competent at camera repair, but I can build computers and install toilets and electrical fixtures, so I'm not totally inept. It's essentially just poking something with a stick, and I'm usually good at that. Is there a trick to it? Is it all an internet hoax? Do I need to say some magic words or sacrifice a goat?

And, if all else fails, is there anyone still repairing these beasts and is it worth going that route?

Thanks, guys!

shutterfinger · Jul 14, 2021

I had a Pro several years ago with a similar problem.
Start by verifying the Mirror release knob is in the normal position, manual page 29 of https://www.cameramanuals.org/mamiya_pdf/mamiya_rb67_pro-s.pdf
Cock and release the shutter on B and hold open. Open the roll holder and remove the insert then look through the camera, you should see the screen the lens is aimed at. Alternatively look through the front of the lens while releasing the shutter, you should see the shutter blades open and close. The Pro S has lockouts that may need to be defeated to accomplish this.
If the shutter does not operate it indicates that the shutter is not being cocked or the shutter is defective.

On the Pro I had the shutter was worn out. I had to take the bottom plate off and release the cocking drive gearing to get the lens off. I did not have a manual to work from.
https://learncamerarepair.com/product.php?product=10&category=2&secondary=22

MattKing · Jul 14, 2021

FWIW, of the four lenses that I had for my RB67 Pro-S, the 65mm C lens was the one whose bayonet mount was the most difficult to release when it had been firmly mounted to the camera.

Neil Grant · Jul 15, 2021

"...the bayonet ring won't budge".
Can't it rotate at all, or just not sufficiently to get the lens off?
Check 'mirror up' is not engaged. Remove rotating adaptor and magazine, cock and fire camera whilst observing ear of camera. Does the camera seem to be 'exposing' ?

If these cameras are working properly they are a 'breeze' to use.

campy51 · Jul 15, 2021

I saw this about a week ago.

DaveInAZ · Jul 15, 2021

First of all, I appreciate all of the help you guys have offered. Very generous of you.

shutterfinger said:
I had a Pro several years ago with a similar problem.
Start by verifying the Mirror release knob is in the normal position, manual page 29 of https://www.cameramanuals.org/mamiya_pdf/mamiya_rb67_pro-s.pdf
Cock and release the shutter on B and hold open. Open the roll holder and remove the insert then look through the camera, you should see the screen the lens is aimed at. Alternatively look through the front of the lens while releasing the shutter, you should see the shutter blades open and close. The Pro S has lockouts that may need to be defeated to accomplish this.
If the shutter does not operate it indicates that the shutter is not being cocked or the shutter is defective.

On the Pro I had the shutter was worn out. I had to take the bottom plate off and release the cocking drive gearing to get the lens off. I did not have a manual to work from.
https://learncamerarepair.com/product.php?product=10&category=2&secondary=22

I don't actually have a B. I have a T on the shutter speed ring. I tried that, but it didn't make any difference as far as removing the lens. I did, however see the shutter move. Unless I've totally confused myself, it's working backwards. It's stuck open and when I trigger it, it closes and then reopens. Maybe I didn't completely cock the shutter before mounting it. I know that's a bad thing, but I'm not sure what the consequences are.

When I'm no longer holding the shutter release button, the shutter remains open. I can look through the camera and see whatever's in focus any time the mirror is up.

And, yeah, I've never encountered so many lockouts on anything mechanical before. That's part of the hate factor.

MattKing said:
FWIW, of the four lenses that I had for my RB67 Pro-S, the 65mm C lens was the one whose bayonet mount was the most difficult to release when it had been firmly mounted to the camera.

Well, I don't think it can get any more difficult than this.

Neil Grant said:
"...the bayonet ring won't budge".
Can't it rotate at all, or just not sufficiently to get the lens off?
Check 'mirror up' is not engaged. Remove rotating adaptor and magazine, cock and fire camera whilst observing ear of camera. Does the camera seem to be 'exposing' ?

If these cameras are working properly they are a 'breeze' to use.

Can't it rotate at all. Like it's welded there. Mirror lock is not engaged, although I tried it to see what would happen. The shutter remained closed after I set that, cocked the camera, and pushed the release button. The camera 'fired', but the lens shutter remained firmly closed until I reset the mirror lock at which point the shutter opened and stayed open.

I thought I was getting the hang of it, last week, but not so breezy now.

campy51 said:
I saw this about a week ago.

Thanks. It basically confirmed the 'poke it with a stick' method and it showed the piece I'm supposed to poke. I'll have to try some more when I get a chance, though I'm no longer sure that solution applies to my problem, given the weird shutter behavior.

shutterfinger · Jul 15, 2021

The shutter is working correctly.
Wear, gear slippage on the shaft, shutter not properly cocked before mounting are possible causes.
Take the bottom plate off, a few screws under the leatherette, cock the shutter via the body lever observing the direction the main drive gear, RS214K2 on pdf page 17 of the service manual, rotation. Once cocked try turning the gear in the same direction as it did while cocking. Do not remove anything else. If you are uncomfortable doing this take the camera to a repair shop.

John Koehrer · Jul 16, 2021

As I vaguely recall, there's nothing that can hang the lens up that engages the bayonet(been a while) so
it's only the ring. being over tightened. Where's the red dot? to get the lens off the dot should be at the top of the lens.
Got a strap wrench, vacuum clean er belt or narrow leather belt?

narrow belt is easier but wide is OK, just a bit harder to handle.

Mamiya_Repair · Jul 16, 2021

I see this issue often on the RB67. If the lens lock ring is stuck at full clockwise (white dot around 3 o'clock), in 95% of the cases the issue is a dented lock ring. The dent may be barely or not visible at all. The technique shown in the mentioned video (which we produced) will only work if the lock ring white dot can be rotated counterclockwise to around the 1 o'clock position as that is where the locking latch contacts the lock ring. My solution is to use a large flexiclamp wrench to remove the lens. The dent then needs to be worked out or the lock ring replaced.

DaveInAZ · Jul 17, 2021

Well, I have good news and bad news. The good news is that I got the lens off without having to take anything apart. The bad news is that I can't explain why it suddenly decided to let go.

I used to have a strap wrench, but it would never grip onto anything slipperier than a cactus, so I tried using my largest pliers. They almost were big enough, but kept slipping off. The camera was cocked from previous efforts, so I tried to release the shutter, which was, of course, locked by something. While trying to figure out which of the hundreds of "safety" locks was "helping" me this time, the locking ring on the lens moved and I was able to fully rotate it and remove the lens. Maybe the pliers got it past the sticking point, after all?

Anyway, I appreciate all the input from you guys. I do have one followup question, if that's ok. I now have that little hole in the leatherette over the hole I was supposed to poke a stick into, and I'm wondering if I need to do something about that. I assumed it would be a problem, but I seem no light leaking in through it. I suppose it could let dust in, but there are much easier ways for that to happen.

What do you think I should do, if anything?

removed account4 · Jul 17, 2021

DaveInAZ said:
What do you think I should do, if anything?

I'd send It to Mamiya Repair....

Mamiya_Repair said:
I see this issue often on the RB67. If the lens lock ring is stuck at full clockwise (white dot around 3 o'clock), in 95% of the cases the issue is a dented lock ring. The dent may be barely or not visible at all. The technique shown in the mentioned video (which we produced) will only work if the lock ring white dot can be rotated counterclockwise to around the 1 o'clock position as that is where the locking latch contacts the lock ring. My solution is to use a large flexiclamp wrench to remove the lens. The dent then needs to be worked out or the lock ring replaced.

Neil Grant · Jul 18, 2021

'shutter locked by something': release locked with knurled collar?, no film in camera?, film not wound on?, film not wound on and multi exposure not engaged?, darkslide not out? As you have found out, the camera has a number of safety features. They are there to stop unintended exposures or unintended film advance. These features are quite common on modular medium format cameras and stop a whole bunch of screw-ups that would otherwise happen all too easily.
'hole in leatherette': roll back the original material and glue.
'locking ring loosened itself': gripping it tightly may have distorted it and then, over a period of time, it relaxed. Do any others lenses get stuck as you described? Something is out of shape or has been dropped.

DaveInAZ · Jul 19, 2021

jnantz said:
I'd send It to Mamiya Repair....

I don't really know my way around this site. How would I do that? I assume you're referring to the Photrio member Mamiya_Repair. Is there a vendor's forum or something?

Neil Grant said:
'shutter locked by something': release locked with knurled collar?, no film in camera?, film not wound on?, film not wound on and multi exposure not engaged?, darkslide not out? As you have found out, the camera has a number of safety features. They are there to stop unintended exposures or unintended film advance. These features are quite common on modular medium format cameras and stop a whole bunch of screw-ups that would otherwise happen all too easily.

You left out my favorite. Has the back accidentally been rotated an invisibly small fraction of a degree off alignment?

Neil Grant said:
'hole in leatherette': roll back the original material and glue.
'locking ring loosened itself': gripping it tightly may have distorted it and then, over a period of time, it relaxed. Do any others lenses get stuck as you described? Something is out of shape or has been dropped.

No, my other lenses do not have any problems with mounting and removing. Just the 65mm.

I must not have explained the 'hole' situation. I didn't do the 'peel it back, use the hole in the body to fix the problem, and reglue the leather' method. I saw someone recommending just making a hole in the leatherette and fixing the problem; no peeling, no regluing. So, I did that. But, they didn't say what to do afterwards. I could just stick a bit of tape over it, but it isn't clear to me whether the hole in the leather is a problem or not.

MattKing · Jul 19, 2021

DaveInAZ said:
I don't really know my way around this site. How would I do that? I assume you're referring to the Photrio member Mamiya_Repair. Is there a vendor's forum or something?

In this case, he includes his website address in the signature part of each post he makes. I would expect that you can reach him through that.
By the way, although we appreciate his contributions here, he is simply a participant, so you should take the normal precautions you would take with any seller of services.
Those may include reading through his posts here. Just click on his name (beside one of his posts), and then click on the number beside "Messages".
Perhaps he will take any contact from you as a sign that it would be a good idea to become a paid advertiser - hint, hint.
If you had more posts here, you could initiate a private message Conversation with him. Perhaps he will see this and your posts, and initiate one himself. You can respond.
Once you have more post activity (20+?) the Conversation function will be available to you - the delay is there to discourage fraudulent activity from spammers and the like.
As for the hole in the leather, I wouldn't worry about it.

Neil Grant · Jul 19, 2021

..'back rotated a fraction off': this isn't an interlock problem. Sounds like excess wear and tear or service needed. Sorry to hear you're having all these problems with what is notoriously reliable camera.

shutterfinger · Jul 19, 2021

DaveInAZ said:
I must not have explained the 'hole' situation. I didn't do the 'peel it back, use the hole in the body to fix the problem, and reglue the leather' method. I saw someone recommending just making a hole in the leatherette and fixing the problem; no peeling, no regluing. So, I did that. But, they didn't say what to do afterwards. I could just stick a bit of tape over it, but it isn't clear to me whether the hole in the leather is a problem or not.

Tape will eventually come off and leave a sticky residue so do not use any.
Apply a very small dab of black silicone rubber over the hole. You might even make it look like the leatherette.

DaveInAZ · Jul 19, 2021

MattKing said:
Perhaps he will take any contact from you as a sign that it would be a good idea to become a paid advertiser - hint, hint.

Done.

MattKing said:
As for the hole in the leather, I wouldn't worry about it.

That was my inclination.

Neil Grant said:
..'back rotated a fraction off': this isn't an interlock problem. Sounds like excess wear and tear or service needed. Sorry to hear you're having all these problems with what is notoriously reliable camera.

Two problems is a lot? It probably does need servicing, but I haven't run an entire roll of film through it successfully, yet, so I'm not willing to make that additional investment until I have seen what kind of results I can produce with it. Well, maybe I have, but I won't know that until I get the negatives back from the lab.

shutterfinger said:
Tape will eventually come off and leave a sticky residue so do not use any.
Apply a very small dab of black silicone rubber over the hole. You might even make it look like the leatherette.

Thanks for the advice. I honestly forgot that there was such a thing as black silicone.

M Carter · Jul 20, 2021

Just an FYI, here's what you're trying to hit when you pull the front leather. That's why ponking a hole isn't as good as peeling, you can't see where you're going:

DaveInAZ · Jul 20, 2021

M Carter said:
Just an FYI, here's what you're trying to hit when you pull the front leather. That's why ponking a hole isn't as good as peeling, you can't see where you're going:

Maybe I'm misunderstanding but, if there was a lens attached, you still couldn't see the thing you're poking. It does appear to be further left (if the camera were upright) than I thought from the other photos I've seen. Thanks.

Tel · Jul 21, 2021

Bill Rogers: mamiyarepair.com
He's in Nevada, not a million miles from you...

DaveInAZ · Jul 21, 2021

Tel said:
Bill Rogers: mamiyarepair.com
He's in Nevada, not a million miles from you...

Well, that's good. Won't cost as much to ship to and from. And he did respond very quickly to my inquiry.

Tel · Jul 23, 2021

Bill's a good guy--he's helped me out with parts in the past and he knows Mamiyas inside and out.

Removing stuck lens from RB67 Pro-S

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Removing stuck lens from RB67 Pro-S

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