MF edge film fog?

I've just got back the first roll of film shot with my "new" medium format camera, a Kowa Six acquired via ebay. The film edge appears to be fogged. Is this normal? Does this mean a light leak in the camera, or film was not rolled up tightly enough when I finished or loaded? Also, I'm not sure you can make it out on this scan (cheap Canon scanner, not meant for film), but at the lower right, at the bottom edge, there'e s little semi-circular divet in the image; it appears on every frame. Have no idea what that's from.

And I brought the film to a local lab to get processed and a contact sheet, and the b*st*rds make it with the negatives in the plastic sleeve. So it's pretty useless. Fortunately, I'm moving in a couple of months, and it should allow me to start doing my own processing.

At least it's not in the image area.

That frame is from the end of the roll. If it's only there, then it's a matter of rolling the film up tightly and keeping it out of direct light when removing it from the camera and thereafter.

If you get this throughout the roll or in varying spots (depending on how long the film stayed in one place before winding and whether direct light was coming in at the right angle), then the problem is light leaking in the film back, and you may need to have the light seals replaced.

The fogging at the edge of the film is undoubtedly due to the fact that the film was not wound tight enough. Check that any flat pressure spring is doing its job properly, and make sure that there are no bulges when you attach the leading edge of the backing paper to the take-up spool, or the film will have no chance of winding properly. The light-trapping on your Kowa is obviously less than perfect, since light from the edges of the negs across the width of the film is creeping under the mask and fogging the film between frames, this may well be a design fault of the Kowa.

Don't curse your lab too much - why are they bastards for contact-printing the film in a transparent sleeve? This is much easier for them and keeps scratches and fingerprints at bay. You should not be using contact sheets to judge sharpness but looking at the film itself, which again is much easier to do without damage if the film is in a transaprent sleeve.

Regards,

David

TThe edge fogging is mainly towards the end of the roll, and I was outside when I changed film (though in shade). I suppose at some point I will have to have the camera checked over by a service person, assuming I can find one who will work on a Kowa. Just getting used to aiming and focusing with the WL finder has been a little challenging. I really hadn't anticipated how much different it is from my Nikon.

I have encountered fog on roll film from inexperienced operators running the film processing machines at labs. The automatic processors require that you unspool the film (usually in a changeing bag) and load it into a plastic magazine, which is then put into the processor the lip of the film is left sticking out, and is taped to a processor leader board, which when fed into the processor pulls the film out and thru the processor. There are many opportunities for fog to occur if procedures are not observed carefully, or the equipment is not maintained well.

The edge fog on the image you posted looks normal to me. I have four "serious" medium format cameras (plus a couple of Holgas and a 120 pinhole camera) and I see this on every roll that comes out of every one of them. Unloading in bright light and the film being slightly loose on the take-up spool is the reason. It can also happen when you leave the film out unwrapped for a several days/weeks before processing. Infrared film shows even more edge fog when loaded and unloaded in bright light. Since the fog never intrudes into the image area, it's no real concern.

I agree with Lee Shively. I won't say it happens to me all the time but it happens a lot and its of no concern- certainly nothing to spend money on if its only as bad as this, though when you do decide to get it checked over its worth making sure that the technician checks out the light traps as would be the case with any MF camera.

The one point I'd make in addition is that if you ever use it, 220 film tends to be worse since it has no backing paper, and it will show up any weaknesses in your management of loading/unloading and storage of rollfilms.

There are a couple of possible causes for edge fogging. What you describe sounds like light creeping in around the flanges of the spool when you remove the exposed film. I say this because you say it happens mostly at the end of the roll. This may be because the takeup mechanism does not wind the film tightly on the reel. That could be related to pressure plate problems as well. You can usually tell pretty easily whether the film is wound tightly just by feeling it - squishiness is bad. A workaround is simply to unload in subdued light and then to keep the film in the dark until you develop it. But if you have consistent problems like this, you should get the camera checked out and repaired.

Another cause for edge fog I found was light leaking through the dark slide slot. Normally, the dark slide slot is sealed to light with some sort of felt and spring loaded wiper arangement. In time, these wear out. Then, when the dark slide slot gets exposed to bright sunlight, some light leaks in and fogs the edge of the film. The workaround is to avoid bright direct sun on the dark slide slot when the slide is removed, and to remove the slide only briefly when you make the exposure. The solution is to replace the light seal, which is a pretty easy repair.

The Kowa doesn't have a removable back (a feature of the later "super 66") so there's no dark slide.

Lee Shively said:

The edge fog on the image you posted looks normal to me. I have four "serious" medium format cameras (plus a couple of Holgas and a 120 pinhole camera) and I see this on every roll that comes out of every one of them. Unloading in bright light and the film being slightly loose on the take-up spool is the reason. It can also happen when you leave the film out unwrapped for a several days/weeks before processing. Infrared film shows even more edge fog when loaded and unloaded in bright light. Since the fog never intrudes into the image area, it's no real concern.

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Lee, you've made the reason your edge fogging doesn't bother you very clear.

I have a slightly different problem, my roll holders take the film up inside out and very consistently don't take it up really tight. My solution is to unload them in a changing bag. Slow, clumsy, makes me look foolish, but its safe.

Cheers,

Dan

When you remove the film from the camera, immediately tension the roll--pull it tight and carefully stick it together tightly.

Second step is to then keep it dark by putting it in a dark bag like a small black garbage bag.

Hmmm. Guess I'm lucky. I have never had a problem with edge fogging. I use Hassy film backs, and either load in subdued light or turn my back to the light source. I don't open the film package until just before I load it, and as soon as I remove the roll, I put it into an opaque black plastic roll holder that I is made and sold solely for holding 120/220 film. I develop all my own black and white film, which eliminates any problems from a lab, although labs that have processed C-41 or E6 films for me have done an excellent job.

Now with the Holgas I used to own, it was a different story.

Pat