Mamiya RB67 and Sekor 180mm f4.5

I have an RB67 and Sekor 90mm and 180mm lenses. When I mount the 90mm everything works perfectly, shutter fires, mirror goes up fully the light baffle opens fully and film is exposed. If I remove the lens and back and fire the shutter, everything works perfectly as well.

 

But when I mount the 180mm, the shutter fires, the mirror goes up but the light baffle only goes up about 10 mm and the film is not exposed.

 

As far as I can tell, both the lens and the body are cocked when I mount the lens and the lens is mounted correctly.

 

Any ideas would be greatly appreciated.

check to see if the baffel is hitting the back of the lens?

 

also, fire the 180 off camera to be sure its not hanging up?

 

is the 180 a C or non C lens?

Doesn't make sense. With the lens installed and body/lens cocked, rack the focus all the way out with bellows fully extended. Try to fire the camera. Try this with both lenses multiple times.

 

What happens?

 

Sounds like a body malfunction. Is the body a Pro, Pro S or Pro SD? If a Pro, it has some age and needs maintenance or to be replaced.

There are different models of lens and of RB67's. I'm not sure all are compatible. Did the 180 ever work or is this a lens you just bought?

The body is a plain RB67 Pro (not Pro-S or Pro-SD.

The 90mm lens is an NB

The 180mm lens has no designation on the front (so presumably Non-C)

 

I bought the body 90mm lens etc. all together, but have just bought the 180mm.

 

The baffle does not hit the lens, if I fire the shutter off-camera everything seems OK. If I extend the bellows all the way out, nothing changes.

 

Thanks for all the quick responses.

Your 180 may have a spacer ring that needs removing first

 

 

The 180mm lens will just work on all models of RB cameras.

 

It may be supplied with a ring to help adapt it to SD models of the RB camera. This is just a spacer ring, that is a friction fit on the back of the lens. To remove it grasp it with two or three fingers and twisting slightly, pull it off. With this ring mounted no lens will fit the Pro and ProS models. So remove it. It's like taking off a lens cap, most people can do that!

 

Link

RB67 lens question / Mamiya KL 180mm f/4.5 L-A | Mamiya RB67 | Flickr

Your 180 may have a spacer ring that needs removing first

 

The 180mm lens will just work on all models of RB cameras.

 

It may be supplied with a ring to help adapt it to SD models of the RB camera. This is just a spacer ring, that is a friction fit on the back of the lens. To remove it grasp it with two or three fingers and twisting slightly, pull it off. With this ring mounted no lens will fit the Pro and ProS models. So remove it. It's like taking off a lens cap, most people can do that!

 

Link

RB67 lens question / Mamiya KL 180mm f/4.5 L-A | Mamiya RB67 | Flickr

There is no adapter ring on the lens, but thanks for the reply

What about the two pins on the rear of the lens, is one or both bent ? Do you know for sure they are positioning correctly in the camera when you fit the lens ?

check if the 180 is in mirror up mode?

Also... when firing the lens off camera, make sure you actually see the shutter open n close when it fires?... you should see light. If not, you are either in mirror up mode or the shutter isnt working properly.

 

There is a very common problem with shutters if they were dropped or sometimes its just age... a tiny spring pops off its post. The spring is responsible for opening n shutting the shutter leaves. Simple fix, but the lens has to be stripped down to get to it. The 180 non C is rather easy to open.

Both pins look fine and the lens is not in mirror up.

All 180mm lenses are compatible with all RB67 bodies provided, in the case of the KL lens, the spacer ring is removed for use with Pro and Pro S bodies.

 

The body is described as a Pro and the lens as a non-C. These are compatible without question.

 

Fire the body ten times, with no lens. What happens?

Fire the body + 90mm lens ten times. What happens?

Fire the 180mm lens by itself, not attached to the body. What happens?

 

It seems the body is the culprit but you need to do some more diagnosis. How long have you had this equipment? Has it always functioned like this?

by deduction... if the camera works with the 90mm, the problem is the lens, not the body.

 

again, fire the 180 off tye body and look through it to be sure the shutter is firing?

btw where are you located?

by deduction... if the camera works with the 90mm, the problem is the lens, not the body.

 

My thoughts also. Somehow the 180 lens is preventing the normal chain of events in the camera from reaching their final conclusion after releasing the shutter - the light baffle only partially operates !

 

I suppose it's possible though that the body has just developed a "light baffle" problem independently of any lens being fitted, but if the body is tested ten times as Wilmarco has suggested, the body might have a clean bill of health if the light baffle works properly each time. However, the action of extending and retracting the bellows apparently can affect the light baffle operation. So perhaps the testing of the body alone, and then with lens fitted, should be carried out while extending and retracting the bellows

 

Link about light baffle sticking in rb67 pros

Mamiya RB67 Pro S Light Baffle Sticking

Everything works perfectly with the 90mm lens and with no lens fitted at all bellows extensions. I think it has to be the lens:-(.

Thanks for all the suggestions, I have only just joined photo.net and am really pleased to see such an active medium format forum. I have only recently added film back to my photography after years of digital and am enjoying the challenge of working with a limited number of exposures and the fantastic results of the medium format.

Btw I am in Somerset, England.

did you fire the 180 off camera and watched the shutter actually open each time?

 

i have a feeling the mirror up lever is stuck and blocking the actuating ring from making a complete cycle.

 

if you were in nyc, id take a look at your lens over coffee.

Agree with Paul, take care to see that the lens is adjusted properly, and test it while removed from the camera. This means the shutter speed is set to something other than "T", and the mirror up knob is set to the red "N".

oh... put a cable release in the mirror up button n fire that too?

BTW. I returned the lens to the seller and will look out for another. Wish me luck!