hallertauBW
Good evening, everyone!
I recently bought a second-hand 6x7 medium-format camera with a 120 film cartridge and am currently trying to figure out what’s wrong.
Out of 10 shots taken, only 7 appear on the negative (same subject, same exposure). The roll film is 81 cm long.
Is that the correct length for 120 roll films? Judging by the length, it could be fine.
Best regards,
Guido
Xenar
Hello Guido,
Without rushing off to the photo lab to measure it: 81 cm is certainly about right for the standard length of a 120 film.
You say that out of the 10 pictures you expected, you only have 7 on the film. Are these 7 exposures very far apart (1)? If not, there must be a long, unexposed section at the start (or end?) of the film (2).
Unfortunately, I don’t know your camera model, but I assume that the transport from one exposure to the next is controlled mechanically in some way (advance mechanism or similar). If (1), then that’s the reason.
If (2), then you’ve probably made a mistake when loading the film into the camera.
Please provide more details, then we’ll certainly be able to help you further.
Regards
Volker
hallertauBW
Good morning Volker,
Thank you for your reply. The camera is a Mamiya RB67 Pro-S. Case 2) applies. At the start, a large section is unexposed and at the end there are still 7 cm left (see photo of the negative). As this is the second time I’ve noticed this (I’ve made other mistakes before), I took care to wind the film in as little as possible when loading it. After closing the cassette, I had to pull the advance lever several times before I could take the first shot. I then took 10 shots following the same procedure until the film could no longer be tensioned, and the first three images are missing from the negative (I have noted down the poses and shooting procedure). At the moment, I can think of the following possible causes:
2a) The first three frames are covered by the paper. (To check this, I’d have to sacrifice a roll of film and rewind it in daylight)
2b) For the first three frames, the aperture was open and provided exposure for several seconds. – But why didn’t this happen with the others?
2c) ...?
Do you have any other tips for me?
Regards,
Guido
Xenar
Hi Guido,
The first 20 cm of the film are black, which means they’ve been exposed – in other words, they’ve been hit with the full force of the light.
It sounds like you’re doing something fundamentally wrong when loading the film. As I’m afraid I’m not at all familiar with the Mamiya, someone else will have to help you out. Don’t you have a user manual?
Best regards,
Volker
hallertauBW
Good evening, Volker,
Actually, I do have a user manual. The section on loading film is rather brief. I’ll give it another go and see how it goes.
Best regards,
Guido
Urnes
Good evening, Volker,
Actually, I do have a user manual. The section on loading film is rather brief. I’ll give it another go and see how it goes.
Best regards,
Guido
You insert the film into the holder. There’s a hole somewhere in the pressure plate. Now reel the film in until you see a black arrow in the hole. Stop there! Then insert the holder into the rear section and use the lever to reel to frame 1. It should fit then.
Regards, Sven.
hallertauBW
Hello everyone,
First of all, I’m completely confused now. Sven, I’ve found what you wrote in the manual too (it’s a white arrow instead of a hole) and I hadn’t noticed that before. In the new series of shots, the first picture now appears (I can tell by the pose). For this image, I’ve now hung both negatives side by side. The one on the left is the new film, wound on ‘correctly’. On the right, you can see that the first three images are missing. But now, on the new film, I only have 7½ frames out of 10 again. What also puzzles me is that there seems to be a jump in exposure in the middle of the film. However, I took the shots using the same aperture, shutter speed and lighting (lamp). Do you have any idea what else I might be doing wrong?
Regards
Guido
Wolf_XL
...well, it actually looks more like a problem with the development... To be absolutely sure that it really is down to the camera, I’d either sacrifice a new roll of film or take one of the failed shots, rewind it with the leader in the correct position, load it into the camera as instructed, remove the lens, set the shutter to ‘B’, press the shutter release and hold it down, and mark the image through the camera with a waterproof felt-tip pen. Mark the rest of the shots in exactly the same way – after that, you’ll be a bit wiser... ;-)
Wolfgg
Hello Guido,
I’d take a very practical approach to this:
1) Take the protective paper from a roll of film and mark the exact position of the film on the back
2) Place the paper on the reel and into the cassette
3) Prepare the cassette so that, even when the lid is open, it operates as if it were closed; to do this, you usually need to hold a pin down somewhere, e.g. with a toothpick (I don’t have an RB)
4) Now proceed as normal: wind forward, then perform an exposure using a longer shutter speed (e.g. 1 sec) and check with each shot whether light from the lens would fall onto the film; this should help narrow down the fault.
Regards, Wolfgang
hallertauBW
Good evening everyone,
First of all, thank you for your suggestions. Yes, that’s pretty much how I did it just now. I curled the negative roll (developed film) back up with the protective paper and placed it in the cassette.
First, I double-checked that the film advance was working. I removed the lens and then took my 10 photos. I marked the area of the negative that would have been exposed during the exposure with a film marker (right and left edges).
Result: 10 separate images on the negative.
Afterwards, I suspected there was a light leak on the side of the mirror or that the lens aperture was ‘leaking’. So I removed the cassette, looked through the film plane into the camera and pointed it at a light source. I couldn’t observe any unwanted light leak. I tried out various apertures and shutter speeds, and also attempted to lower the mirror only partially (which would have been an operating error).
Result: Everything works perfectly, and it was fascinating to see how it all works.
As for the development fault, the only thing I can think of is that the film might be stuck together and the developer can’t reach it, but then the negative area would be transparent, wouldn’t it?
Regards, Guido
Wolfgg
If only the fixer is applied but not the developer, the film becomes transparent; if neither is applied, it remains as good as new, i.e. grey and opaque.
Best regards, Wolfgang
hallertauBW
Good evening everyone,
I’ve found my mistake. Whilst writing my last reply, a nasty suspicion crossed my mind, and it has been confirmed. I’d bought a Paterson developing tank specifically for roll films, designed to hold two 135 films or one 120 film. The two film spirals (135) are held together by a small black tube. Naturally, I left this tube out when using the 120 spool. And that’s precisely why light (from outside) got in through a few grooves in the inner bore of the spiral. That also explains why the negative strips had extra exposure in two stages (three frames black, three and a half frames darker). Grrrrrrrrr
Thanks for your help; it made me rethink the situation.
Best regards,
Guido
Xenar
Hello Guido,
Congratulations on finding the fault. I didn’t reply to your second example photo because I was at a loss. Only one thing seemed clear to me: it must be a handling error, though I was only thinking about loading the film; the development process didn’t occur to me.
Best regards,
Volker
