Switching lenses on RB... whats the trick?

[avandesande]

I switched the lenses a couple of times mid-roll and it ended up blackening the frames that were active when I did it. It was cocked when I switched lenses and I could see the mirror was down... however after I made the switch the shutter wouldn't fire (on manual) and I had to re-cock it to get it to go.
Is there a trick to this or do I have to put the slide in the back and remove it to do this right?

 

[Steve Smith]

I've only had my RB for about a month but I haven't had any problems changing lenses. All I know is that the body and lens need to be cocked to remove or replace the lens and that the shutter will not fire if the darkslide is in place.

If you got black frames then light obviously got in whilst you were removing the lens. You should definitely put the dark slide in when you do this but there is no need to to remove the film back from the body.

Steve.

 

[avandesande]

You cant fire the shutter if the darkslide is in, and as I mentioned the shutter wont work correctly unless you fire it and recock it. That's why I think I may have to remove the back.
I don't think the body is broken, it's a plain RB, maybe they fixed this in the later versions.

 

[Travis Nunn]

I've not experienced this problem either and I've had my RB for about a year and a half. At least on the ProS body, the mirror has to be cocked before the lens can be removed. Could it be that you tripped the shutter with the lens off? Did you have it on MLU?

 

[dalahorse]

I switched the lenses a couple of times mid-roll and it ended up blackening the frames that were active when I did it. It was cocked when I switched lenses and I could see the mirror was down... however after I made the switch the shutter wouldn't fire (on manual) and I had to re-cock it to get it to go.
Is there a trick to this or do I have to put the slide in the back and remove it to do this right?

When the body is cocked, a dark flap behind the mirror should block light from reaching the film. Perhaps that flap is not making a good seal.

 

[avandesande]

I always have it in 'M'(MLU) mode. I don't think it is any sort of light leak, because the frame is uniformly dark.

Perhaps leaving the lens caps on is enough...

 

[Steve Smith]

If it's in Mirror Lock Up mode it would be possible to accidently press the shutter causing the the mirror to lift and the flap to uncover the film. If the lens is then taken off, the film will be exposed.

Steve.

 

[Travis Nunn]

If it's in Mirror Lock Up mode it would be possible to accidently press the shutter causing the the mirror to lift and the flap to uncover the film. If the lens is then taken off, the film will be exposed.

Steve.

That was my thinking exactly.

 

[paul ron]

If you are in MLU then your shutter may not be cocked and that can lock a lens on the body where a pro repairmen might have to remove it for you. Be sure the lens is in "Normal", cocked, same for the body.

 

[David Brown]

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

This is for the ProS. Manuals for the Pro and ProSD are also on the Mamiya website.

Just FYI

 

[avandesande]

Thanks. I will do it this way for now on...

If you are in MLU then your shutter may not be cocked and that can lock a lens on the body where a pro repairmen might have to remove it for you. Be sure the lens is in "Normal", cocked, same for the body.