Why is my HB A12 film back suddenly malfunctioning?

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bags27

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I don't use the HB 500 c/m as much as I might, but recently, about every other roll is coming out of the film back backwards! I don't know why that is. I'm 99% sure I'm loading the film correctly. (I've even checked with several on-line videos). Am I overwinding the film after the 12th shot? That doesn't seem like it could be. Does anyone ever have this problem? thanks!
 

BrianShaw

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You must be loading the film incorrectly. It may feel wrong but the printed side of the backing paper is down and the black side is up.
 
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bags27

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You must be loading the film incorrectly. It may feel wrong but the printed side of the backing paper is down and the black side is up.

I have to think you're right. But the arrow on the film is always visible and I always line it up with the red arrow on the back. If that's the case, I can't be loading it the wrong way, can I?
 

BrianShaw

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If you see the arrow you should be loading correctly. Is the sticky tape correctly visible when you removed the film?

I have no other explanation to offer other than a voodoo curse or hobgoblins.
 
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bags27

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If you see the arrow you should be loading correctly. Is the sticky tape correctly visible when you removed the film?

I have no other explanation to offer other than a voodoo curse or hobgoblins.

Thanks so much, Brian. If you mean the sticky tape that holds the film to the backing, no. If you mean the tape we lick that secures the roll of film, yes. But it seems to be in the wrong place: under the film, rather than over it. When I've developed these rolls (twice), I get no photos. Either completely over-exposed or completely unexposed: I'm not sure which.

Anyone able to undo a voodoo curse? 😀
 
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bags27

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Searching for answers, what exactly does he mean that the backing paper must engage with the take-up spool? Just that it has to be tightly wound?
 

reddesert

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You should be able to tell the difference between a roll of film that was not exposed at all (clear with frame numbers) and a roll that was light-struck (dark) by looking at the negatives.

You can practice loading with just a roll of backing paper so as not to waste film. Load, fire off a few shots, open the dark slide and the back to see if the paper is the right way around.

My guess is that (far fetched as it seems) you're loading the supply spool the wrong way around and the takeup spool somehow just enough to see the arrow, but then in-camera it reverse winds and winds the paper+film forward, meaning that it winds onto the takeup spool wrong side out, because the supply spool is wrong side out, so the film doesn't see light.
 

BrianShaw

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What he means by “engaged” is that the backing paper is far enough in the spool slot to not come loose. That isn’t your problem since being disengaged would mean that the film won’t transport from the supply to take up spool.
 

cramej

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I have to think you're right. But the arrow on the film is always visible and I always line it up with the red arrow on the back. If that's the case, I can't be loading it the wrong way, can I?

The start arrow will show no matter which way you've loaded the film. When you wrap the backing paper around the pressure plate side of the insert, you should be looking at the black side, not the printed side.
 
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bags27

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The start arrow will show no matter which way you've loaded the film. When you wrap the backing paper around the pressure plate side of the insert, you should be looking at the black side, not the printed side.

Thanks. I do see the black side.
 
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bags27

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You should be able to tell the difference between a roll of film that was not exposed at all (clear with frame numbers) and a roll that was light-struck (dark) by looking at the negatives.

You can practice loading with just a roll of backing paper so as not to waste film. Load, fire off a few shots, open the dark slide and the back to see if the paper is the right way around.

My guess is that (far fetched as it seems) you're loading the supply spool the wrong way around and the takeup spool somehow just enough to see the arrow, but then in-camera it reverse winds and winds the paper+film forward, meaning that it winds onto the takeup spool wrong side out, because the supply spool is wrong side out, so the film doesn't see light.

Thanks so much for this.

If I shoot a roll with only the backing paper and open the back, which way should the printed side be facing?

How could the supply side be loaded the wrong way? I've thought about that, and just don't see how the mechanics of the back (A 12 III) allow that? So long as the take up is above the "Hasselblad" with the turning roll, and since the knob turns in only one direction, I don't know how I'm doing it wrong.

So, I go back to the question; could I be rewinding the exposed roll too rigorously? When rewinding a 35mm camera, it's easy to feel when there's no longer tension. And you can't overwind the canister. Ditto my various other MF cameras for a variety of reasons. But I often give the HB "extra" winds, "just to be sure." Am I somehow flipping the film so that it rolls over the back-up paper? I dunno?....
 
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BrianShaw

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Load a backing paper and pull the dark slide. You should see black.

There is no such thing as “rewinding” 120 in a Hasselblad (or any other 120 camera, I believe). The film winds from supply to take up spool; one direction only.

There’s only 2 ways to load the supply side. Black side out (the correct way) and flipped over with printed side out (incorrect way).

The most damage you can possibly do with a few extra winds at the end is tear the sticky tab that secures the exposed film roll. There is no way for the film to flip inside out at that point. Unless a TommyKnocker is messing with you.
 
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bags27

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Load a backing paper and pull the dark slide. You should see black.

There is no such thing as “rewinding” 120 in a Hasselblad (or any other 120 camera, I believe). The film winds from supply to take up spool; one direction only.

Thanks again, Brian.

Yes, stupid me! I'm not "rewinding": I'm actually "forwarding." I'm wondering whether I'm forwarding too much until the lick-tab somehow gets in between the back and the film and begins to invert them.
 

reddesert

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Think about this.

If you load the backing paper, and shoot up to exposure 3 or so, then open the back, you have to see the black side of the paper in the film gate, facing the lens. That's where the film would be. The paper should be wrapping around the takeup spool with the printed side out.

I assume you're talking about winding off the paper trailer after exposure 12, not rewinding, because there isn't any rewinding with 120, as Brian said. It shouldn't really matter how fast you wind those off.

Only the takeup spool pulls on the paper+film. So it is at least theoretically possible to load the supply spool backwards and have the takeup spool pull an entire roll of film through the back with the backing paper not the film facing the lens. I don't know if this is actually possible with a Hasselblad back.

In order to get no exposure on the film, it has to be backwards when it's in the film gate, not just on the supply spool. You can't invert an entire takeup spool of already-wound film by pulling on the lick-paper. Really, just practice it with a spool of paper and you should figure out what's happening.
 

BrianShaw

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Is this factory sealed film? If so, I see no way for the film to do a somersault inside the camera back.
 
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bags27

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Is this factory sealed film? If so, I see no way for the film to do a somersault inside the camera back.

Yes, Porta. So it's a lot of money per screwed up roll. And maddeningly, like I said, it's about every other one over the past couple of weeks. I've lost a lot of shots I wanted to develop.
 
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bags27

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Think about this.

If you load the backing paper, and shoot up to exposure 3 or so, then open the back, you have to see the black side of the paper in the film gate, facing the lens. That's where the film would be. The paper should be wrapping around the takeup spool with the printed side out.

I assume you're talking about winding off the paper trailer after exposure 12, not rewinding, because there isn't any rewinding with 120, as Brian said. It shouldn't really matter how fast you wind those off.

Only the takeup spool pulls on the paper+film. So it is at least theoretically possible to load the supply spool backwards and have the takeup spool pull an entire roll of film through the back with the backing paper not the film facing the lens. I don't know if this is actually possible with a Hasselblad back.

In order to get no exposure on the film, it has to be backwards when it's in the film gate, not just on the supply spool. You can't invert an entire takeup spool of already-wound film by pulling on the lick-paper. Really, just practice it with a spool of paper and you should figure out what's happening.

Thanks so very much with this. I've practiced with paper only, and when I check after firing several shots, I saw only the black side of the paper. I'm 99% sure this is how I've been loading the film all along. It's a pretty idiot proof process (but only "pretty idiot proof" and I can be a complete idiot). I just can't figure out what I'm doing wrong.

But really appreciate all the help!
 

reddesert

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To be clear, this is what I think happened. Clearly this doesn't happen all the time since you get some rolls that are good. But for the rolls that are blank and wound the wrong way on the takeup spool, perhaps you were in a hurry, and I think you loaded the supply spool the wrong way around. This is a Kiev back so it doesn't have a start mark, but I lined up the backing-paper arrow with about where the Hasselblad start mark is. The supply spool is on the left, and the take-up spool is on the right and the film is winding onto it inside-out. It is possible to line up the paper arrow, but feed the film back-to-front.


IMG_0884.jpg
IMG_0885.jpg
 
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bags27

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To be clear, this is what I think happened. Clearly this doesn't happen all the time since you get some rolls that are good. But for the rolls that are blank and wound the wrong way on the takeup spool, perhaps you were in a hurry, and I think you loaded the supply spool the wrong way around. This is a Kiev back so it doesn't have a start mark, but I lined up the backing-paper arrow with about where the Hasselblad start mark is. The supply spool is on the left, and the take-up spool is on the right and the film is winding onto it inside-out. It is possible to line up the paper arrow, but feed the film back-to-front.


View attachment 315706 View attachment 315707

I'm sure you're right!! This is the only way i can think of that it can be configured wrongly and still have the arrow match up.

Thanks so much.
 

eli griggs

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If you see the arrow you should be loading correctly. Is the sticky tape correctly visible when you removed the film?

I have no other explanation to offer other than a voodoo curse or hobgoblins.

Some dark Force has placed a curse on you, so you must get a leap year Mercury dime and wear it on your ankle, preferably with a silver chain but, a strong cotton or linen cord will do the trick.

Good luck.
 
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