Mamiya RB67 problem

[Bernard Kelly]

I have a consistently occurring problem with my Mamiya RB67 Pro SD:

On every third frame (of ten) there's a mark that looks like a kink in the film (see photos).

This happens no matter which of three film backs -- or which of three lenses -- I use. And, as I say, it appears only on the one frame per roll.

Any ideas on what might be causing this?

 

[mshchem]

That's weird. I have RZ67 II. Two bodies multiple backs, never seen anything like that.
No problem loading development reels?
Maybe shoot a roll of C41 and have it developed by a minilab.
????

 

[MattKing]

How are the seals in the rotating adapter?

 

[Ariston]

My thought is the same as mshchem. Are you sure it’s not something in the way you load your reels?

 

[Trail Images]

How are the seals in the rotating adapter?

I thought of the same or a similar problem of sorts. Basically some kind of light leak.
However, I see it is with a ProSD body. I was under the impression SD's did not have any seals to worry about. I've been using the same SD for 20+ years now and have not had this as any issue. So, I'm very curious as to what might be taking place on this item.

 

[Bernard Kelly]

You're right. It must be the way I load the reel. I just had a look at some colour negs I had processed at the lab and there's no such mark.

Which makes me wonder what I'm doing wrong. When I've wound the whole roll, I usually stop when I come to the end and don't wind any further. Am I stopping too soon?

 

[shutterfinger]

What reel/tank combo? (stainless steel or plastic twist reel)

 

[mshchem]

I use IR goggles to load Jobo reels. The Jobo reels work fine as long as you know the tricks. I find Paterson easy, the AP reels have added guides. Stainless just comes from practice. A good SS reel goes very quickly for young agile fingers.

With any plastic reel, but especially Jobo if you just barely nip the corners of the leading edge of the film it goes much smoother. I have always loaded reels sitting in a cool, dark room, at a table. At nearly 63, my fingers aren't as nimble as in my youth.

 

[Bernard Kelly]

I use a Paterson tank and plastic AP reels with those extra large flanges. Loading s always pretty smooth; I don't force it. What I wonder, as I said before, is whether I should wind the tail end of the roll a little farther on. Maybe it's curling up a bit and ... doing I don't know what ... pressing on the film below it?

 

[MattKing]

I would check to make sure your Paterson tank is undamaged - which version of Paterson tank is it - universal, System 4 or Super System 4?
I had a crack in one of my Super System 4 tank. On another of my Super System 4 tanks the adhesive holding the red ring gave way. In both cases, the failure was after many years of service and the repair was easy.

 

[MattKing]

You might also try loading a film on to the reel in the other direction, to see if the light leak moves to frame 7 (or so).

 

[Andrew O'Neill]

If you haven't cut/sleeved the negatives, try spooling it again on the reel, watching carefully to see if anything out of the ordinary occurs. I have same camera and development tank, and have never seen this.

 

[Bernard Kelly]

Thanks for all your suggestions.

It's a Super System 4 tank that I bought a month ago. The mark first appeared while I was using the previous (old) tank, has persisted with the new one.

I have a roll of film in the tank right now. I'm going to make a little change in the spooling and see whether that makes a difference.

I'll report back here when the film is developed.

 

[shutterfinger]

I use stainless steel tanks and reels primarily but have Jobo 2500 tanks and reels for 120 and 4x5. When loading 120 on any reel I run the back side of a fingernail along the edge of the film after each full revolution of the reel ( 1 turn ) to verify the film has wound smoothly. Any irregularity will be very noticeable. I also bend the outer end of the film, about 1/8 inch, outward from the center to prevent it from touching the next turn under it.

 

[Bernard Kelly]

No luck. Same result. All I've established is that the tail end of the film isn't the cause. Nor, I imagine, is the leading edge, which bends out rather than in.

My next step, I think, will be to try a non-Ap reel, just in case there's something faulty about the two I have. (Not likely, but -- faintly -- possible.)

 

[MattiS]

Just a guess - maybe itˋs a problem of peeling off the adhesive tape from the end of the film too fast. That can cause light effects on the film. And depending on the reel diameter it could very well be the „right“ place.

Ìm pretty sure itˋs neither a light seal issue of the camera nor a light leak in the tank - there are no light marks outside the frame on the borders.

 

[shutterfinger]

The film does not have to be touching to cause those marks. Measure the distance between the groves in the reel. If the end of the film is curving toward the next layer and reducing the space by 50% or more it will cause insufficient chemical flow between the rounds of film resulting in under development at those spaces.
Refixing the film may help clear them.

 

[MattiS]

... If the end of the film is curving toward the next layer...

But this will not happen on the emulsion side of the second layer which faces to the center of the reel. Can it still cause these marks?

 

[shutterfinger]

Innermost curving upward will.

Film should be loaded with the emulsion facing inward toward the center of the reel on any reel type.

 

[mshchem]

No luck. Same result. All I've established is that the tail end of the film isn't the cause. Nor, I imagine, is the leading edge, which bends out rather than in.

My next step, I think, will be to try a non-Ap reel, just in case there's something faulty about the two I have. (Not likely, but -- faintly -- possible.)

I have used Paterson reels for 40 years. When I tried the AP reels it was a surprise, I had a heck of a time. My younger friends grew up with AP and have no troubles. Nice new clean Paterson reels are great. Snipping a tiny bit from the corners of the leading edge helps A LOT with plastic reels. If you look on youtube there's videos on loading Jobo reels that show the snipping. If you snip too much the film falls off the reel, just right and the film slides on like a dream.

 

[Ariston]

I have used Paterson reels for 40 years. When I tried the AP reels it was a surprise, I had a heck of a time. My younger friends grew up with AP and have no troubles. Nice new clean Paterson reels are great. Snipping a tiny bit from the corners of the leading edge helps A LOT with plastic reels. If you look on youtube there's videos on loading Jobo reels that show the snipping. If you snip too much the film falls off the reel, just right and the film slides on like a dream.

I used to snip corners and had the hardest time loading the reels. When I stopped snipping, it became so much easier. I always heard how snipping helped so much... I don't know what is wrong with me, but it is backwards for me!

 

[mshchem]

I used to snip corners and had the hardest time loading the reels. When I stopped snipping, it became so much easier. I always heard how snipping helped so much... I don't know what is wrong with me, but it is backwards for me!

It's a very fine line between enough and too much. I never snipped until the wonderful world of Jobo hit me about 5 years back. I need IR goggles to load Jobo reels. Granted I'm old and fumble fingered. I even went so far as to buy a small 3 position die cutter to snip a round corner on the film. I've found it needs to be a tiny cut or it makes matters worse. The other trick I've learned here is to rub your finger tips on the sides of the reel to push the film into center.

Until I hit 50, I used nothing but Paterson, never had a problem. Then I got a used Jobo, I love anything that costs money and makes things more complicated .

 

[Ariston]

I love anything that costs money and makes things more complicated .

A man after my own heart!

 

[MattKing]

If you want to snip corners, nail clippers work great.
I think the AP reels are great - I have a devil of a time loading 120 into Paterson reels with (effectively) 1.5 hands.

 

[Bernard Kelly]

I'm very grateful for all the comments received, both here and in private conversation.

Some context:
I've been developing roll and sheet film for several years, 120 film in various sizes (6x4.5, 6x6, 6x9, even 6x17). Which is merely to say I've made more than my fair share of mistakes. But it was only when I started using the RB67 in January of this year that the mysterious mark appeared. Hence my belief that the camera itself was at fault.

A belief I no longer hold, as it now seems most likely that in spooling the film I've somehow (and all too consistently) encouraged the leading edge to interfere with the development of the frame opposite it on the reel. (Looking at the roll as it hangs to dry, I can see quite clearly how winding brings these two together.) So it's not the camera or the film back or the reel or the tank ... it's me.

Back to basics:
When, in the dark bag, I remove the paper backing from the film, I hold the roll in my left hand and unwind the paper with it until the film emerges, which I then collect in my right hand until both parts have unrolled, at which point I separate them with a gentle twist. (BTW: Is the emulsion on the inside or the outside of the curl? I've always assumed the inside. Now I'm not sure.)

The next two steps I've begun to question:
1) I then cut off the film edge with the tape on it, making a new edge more or less even. Should I not do this but simply peel off the tape? (I don't know why I do this; I suspect it's to prevent tape residue from contaminating the film.)
2) In guiding the film edge onto the reel I usually pull it past the ball bearings. Should I not do this but expect the bearings to do the pulling themselves?