Mamiya RB67 Troubleshooting

[JADoss23]

Hey gang,

I recently bought a Mamiya RB67 and it came with 120, 220 and polaroid back. I wanted to test it when I got it so loaded a pack of fuji fp in the polaroid back and shot a couple test shots and got exposures that looked fine. However after I ran two different 120 rolls of b&w film and developed I've come out with blank negatives. It wasn't a developing error because the info on the film showed there just wasn't an exposure. I assume I did something wrong in the shooting process? Maybe the way I loaded the film or could be anything. Any help is appreciated! Thanks

 

[markbarendt]

You are saying that 'the info on the film', does that mean the edge markings like 1 2 3 and Tri-X or whatever developed properly?

If so, was the dark slide removed?

 

[JADoss23]

Yea, sorry was drawing a blank on the right term. haha. Yes, the markings were clear and visible. I did remove the dark slide.. Does it need to be put back in between shots?

 

[chassis]

The darkslide does not need to be replaced between shots.

Sounds like the film spool was loaded upside down which would result in the backing paper facing the lens, producing blank negatives, but with edge markings visible after processing.

 

[JADoss23]

Would I still see the arrow that shows you when to stop the film if it was loaded upside down?

 

[MattKing]

Which version of RB67 - "Pro", "Pro-S" or "Pro-SD"?
The different film backs + rotating adapters have different safety interconnects. And if I recall correctly, the polaroid back doesn't make use of the rotating adapter.
It may be that there is a problem with the interconnects and/or the rotating adapter, such that the shutters on the lenses aren't releasing when they should.
Try loading the backing paper into the film back, advance it normally, and then watch the leaf shutter as you release the shutter release.
By the way, if you load it properly you will see the arrows that show you where to stop the film. My question would be - what did you see when you opened the back at the end? Was the "exposed" sticker there?

 

[chassis]

Another possibility is the mirror lock up knob was in the "M" position. This condition applies only to non-C and C lenses. It does not apply to KL lenses.

 

[markbarendt]

Ok, one of the beauties of the RB is that there are ways to visually confirm what's happening without wasting film.

Fully assemble the RB so that it is basically ready to shoot with the exception of the dark slide. Pull the dark slide out only until the triangle is just fully visible. In this condition the camera should behave normally but the film won't be exposed when you operate the camera.

Do not advance the film between shots instead just reset the Dbl exposure lever on the film back, that clears the interlock.

Cock and fire the shutter while looking in the front of the lens. Did the shutter work? (Most easily seen at at slower speeds.)

Cock and fire the shutter while looking in the viewfinder, does the mirror swing up as you find the shutter?