120 film - light leak between frames

I have a Pentacon Six 120 film camera and I am suddenly experiencing some kind of strange light leak on my films. Below, I have added a scan of the first three exposures on a roll and as you can see, at the beginning og the film, even the space between the exposures is affected. The vertical position of the mark is always the same, but it moves left and right relative to the actual exposures. On this particular roll, the streaks seem to move further left into the actual exposure for each frame, but on other rolls, they jump back and forth. On this roll, all exposures were affected, but I have also shot rolls where only some of the exposures have marks on them, and some rolls in between without any issues at all.

All films, with which I have had the problem are from the same brand (Rollei), but I have had issues with both RPX 100 and RPX 400 films and have shot many films from the same stock without issues, so I doubt that it is something wrong with the films. I am doing pretty straight forward stand development in a Jobo tank and have not changed anything to the way I have been developing films for years. Yesterday, I developed two rolls together and I had only marks on one of them.

Has anyone of you an idea what might be causing this?

I would guess it is from a combination of a light leak and an internal reflection in the camera. The fact that it overlaps both the image area and the area between the frames points to it occurring as part of the winding process - possibly some sort of flexing, combined with a failing light seal.

Hmmm. Check your cloth shutter curtains to see if there have been holes open up along the metal seam. Dry fire and wind the shutter slowly while pointing a bright light directly into the lens in a dark room.

My vote is for physical damage/stress to the film, likely after exposure and unloading. One portion of the roll seems to have been crushed, damaging the emulsion which then develops darker.

Best,

Doremus

I also think this is not due to faulty film, but something with the camera. Could be some mechanical stress to the film or a light leak. I´d inspect the camera for two things: light leaks as described by Kino and some mechanical damage inside the film compartment. Maybe some part to hold the film in position is a little bent, or there is something sticky/ some debris/ dirt stuck inside the camera which affects the film during transport.

I would say film damage due to stress. It is not a film issue, but a camera issue.

Kino said:

Hmmm. Check your cloth shutter curtains to see if there have been holes open up along the metal seam.

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You almost nailed it. There are no holes along the seam, but the cloth itself (near the seam) has some kind of damage to it, so that light comes through. The cloth is not torn and there is no obvious and visible damage to its surface, but if I hold the camera toward a bright light when winding, I can see some faint lines of light through the cloth, which match the streaks on the film.

The defect is probably only noticeable if I wind the camera in bright light without having a lens cap on. As I wrote, I only had the issue with some films and sometimes only on parts of the film, but coming to think about it, all affected pictures were taken outside in bright sunlight and with those pictures *not* affected, although taken in bright light, I might have had the lens cap on when winding the camera.

Doremus Scudder said:

My vote is for physical damage/stress to the film, likely after exposure and unloading. One portion of the roll seems to have been crushed, damaging the emulsion which then develops darker.

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My first impression was pressure marks too.

AgX said:

My first impression was pressure marks too.

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But as I already wrote, it is not.

I am not familiar with the construction of the Pentacon Six shutter, but assume it is multi-layer black silk or some form of cloth. The thin areas you see might be on the inner layer of the shutter. It could be a stress pattern that pulled threads, it might be mold damage that has gone undetected or even burns in the cloth from sunlight striking the surface for an extended period of time.

Short of having the shutter cloth replaced, you could try always hand-capping the lens when advancing the film to see if the problem goes away.

Kino said:

I am not familiar with the construction of the Pentacon Six shutter, but assume it is multi-layer black silk or some form of cloth. The thin areas you see might be on the inner layer of the shutter. It could be a stress pattern that pulled threads, it might be mold damage that has gone undetected or even burns in the cloth from sunlight striking the surface for an extended period of time.

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I am not sure exactly which material it is, but it is some kind of coated cloth. After examining the damage closer, the cloth itself looks intact (there are no broken threads), and it seems as if some of the coating is missing. It is unlikely a sun burn, as the damaged part is only visible during winding (the shutter is cocked together with the film transport) but after some Googling today, it seems to be a common problem with the Pentacon, that lubricants can attack and dissolve the coating. I had the camera in for maintenance last month and perhaps something went wrong when they cleaned and lubricated the mechanics. Such damage can allegedly be easily repaired by patching the damaged area with a layer of liquid latex. I have ordered a small bottle today and hope that I can repair it myself.

Putting on the lens cap while winding the film actually solves the problem as well.

Good. Hope this solves your problem! I always wanted a Pentacon Six, never found one at a reasonable price, so I got a Kiev 88.

At Apug are some reports of members sealing holes in cloth shutters, with flexible varnish.

Kino said:

Good. Hope this solves your problem! I always wanted a Pentacon Six, never found one at a reasonable price, so I got a Kiev 88.

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I think it did. I didn't want to apply too much at once, one layer didn't suffice, but now after the second layer has dried, there are at least no visible light leaks anymore and the shutter seem to work as expected.

Just out of curiosity: What would you consider a reasonable price for a Pentacon? I am not selling mine, but at least here in Germany, Pentacon cameras are much easier to obtain and tend to go for a lot less than the Kiev 88.

When I was actively hunting for one, I was looking to pay $175 to $200 USD for a good functional body and 80mm lens.

But in the process, I found a great deal on a Kiev 88 kit.

I paid approximately $350 for a Kiev 88 with a Mir 45mm F3.5, Mir 65mm F3.5, Arsat 80mm F2.8, Vega 120mm F2.8, Kaleiner 150mm F2.8 and a Arsat 250mm F3.5, with TTL viewfinder, waist level viewfinder, extension tubes and 5 backs in a water tight shipping case.

After that, I stopped looking!