Mamiya C220. Light leaks?... Help!

Ulrik Christiansen · Dec 6, 2023

Okay, I have a problem which has been nagging me for a while. Pictures below.

I have two Mamiya C220 cameras and this "anomaly" happens with both of them. My negatives show some kind of light leak or too much exposure at both sides. It does not happen always, but often. Sometimes it is not so severe, sometimes it takes quite an effort to combat in post. I am almost always able to make it okay in post, but of course, I am interested in finding out what is wrong.

Since it is happening with both camera, with the second having had a CLA maybe 2 years ago (by another owner), I think it must happen in the steps after I have removed the film from the camera. I have tried removing the film from the camera inside my darkbag, which didn't help.

I use a standard Patterson tank with a white plastic wheel. I agitate using the stick but at the same time I sort move the tank around in circles

I most often use DD-X in 1+9 dilution.

Any ideas what I am doing wrong?

I do not see any of these light leaks when developing 35mm film in the same tank.

Kino · Dec 6, 2023

It may not even be a leak...

Try snapping on the cap and doing inversions for agitation. This might be due to the developer not being randomly distributed across the surface of the film. The edges of the reel would cause more agitation than the center and could be contributing to increased density on the edges.

MattKing · Dec 6, 2023

It would help if we could see a backlit digital photo of the negatives themselves, with edges of the film rebate and space between the frames showing.
Do you use 120 film in any other camera? If so, do you see the problem then?
When you say "standard" Paterson tank, are you referring to the current Super System 4 tanks, or the predecessors?

Ulrik Christiansen · Dec 6, 2023

Kino said:
It may not even be a leak...

Try snapping on the cap and doing inversions for agitation. This might be due to the developer not being randomly distributed across the surface of the film. The edges of the reel would cause more agitation than the center and could be contributing to increased density on the edges.

That is actually a very plausible explanation, I would think. Thanks! This Sunday I will try to shoot a roll normally and then develop it with rotational agitation including the cap.

Ulrik Christiansen · Dec 6, 2023

MattKing said:
It would help if we could see a backlit digital photo of the negatives themselves, with edges of the film rebate and space between the frames showing.
Do you use 120 film in any other camera? If so, do you see the problem then?
When you say "standard" Paterson tank, are you referring to the current Super System 4 tanks, or the predecessors?

I just checked some 120 scans from another camera, and I see the same here there.

It must be the predecessors, since it was my dads.

Kino's answer above seems spot on - worth a try. Oh, I hope that is the solution . If not I will make some digital images of the negatives and post here. I'll report back soon.

Thanks for your replies Kino and Matt!

Sirius Glass · Dec 6, 2023

The light leaks may come from the exposed roll not being rolled tightly enough or light piping in from the edges. To avoid that problem I recommend using black plastic film holders. Also put masking tape or painters tape on the holder to be used to seal the exposed roll more securely than with the paper tape supplied with the film. Doing that eliminated my 120 film light leaks. See below:

Japan Camera Hunter 120 Film Hard Case Olive - Holds 5 Rolls of 120 Size Film

Japan Camera Hunter 120 Film Hard Case Olive - Holds 5 Rolls of 120 Size Film - If you are looking for a suitable way to store and transport your films, then you are in the right place! The Japan Camera Hunter…

www.freestylephoto.com

250swb · Dec 7, 2023

Two cameras both doing the same thing isn't impossible but it is improbable, so it's likely to be some outside influence common between the two. I agree with the 'fat roll' theory, not keeping tension on the film leader as it's first wound onto the take up spool. But that can also lead to only getting 11 1/2 frames instead of 12, so does the frame spacing ever look inconsistent? I don't buy the agitation theory, the twiddle stick is good until you are into tens of minutes of development and then one invert can be enough mix it again. If the developer was exhausting itself, or an external leak in the tank etc. I don't think the increase in density would show equally along both edges.

Ulrik Christiansen · Dec 7, 2023

250swb said:
Two cameras both doing the same thing isn't impossible but it is improbable, so it's likely to be some outside influence common between the two. I agree with the 'fat roll' theory, not keeping tension on the film leader as it's first wound onto the take up spool. But that can also lead to only getting 11 1/2 frames instead of 12, so does the frame spacing ever look inconsistent? I don't buy the agitation theory, the twiddle stick is good until you are into tens of minutes of development and then one invert can be enough mix it again. If the developer was exhausting itself, or an external leak in the tank etc. I don't think the increase in density would show equally along both edges.

Hm, okay. I always wrap some rubber bands around finished rolls as soon as I take them out of the camera. They seems to be very tightly wound in the camera and the frame spacing is perfect for 12 frames.
Thanks for your input

Dan Daniel · Dec 7, 2023

Those sure look like uneven development to me. As Kino described. Not sure what your tank allows. I've found that inversions reduce this. Quick flips but pause between each inversion. Flip, count to 2, flip, count to 2... Need time for fresh developer to move around and reach the center.

But if the film edges show exposure, then yep, light leaks. Which should become less and less as you move inward on the spool, i.e. toward the first frames on the roll.

Ulrik Christiansen · Dec 17, 2023

Well. Case solved.

I shot a roll of HP5 today and developed it with inversions as agitation. I see no artifacts on the negatives. The sides look as they should with no uneven development or anything.

So, my lesson learned is: Do not use the stick for agitation, use proper inversions.

Thank you everyone for replying and helping me get my procedures right

Here are a few postprocessed shots from the roll today:

Kino · Dec 17, 2023

Very nice. Glad you were able to rectify the situation!

Eff64 · Dec 18, 2023

Thanks for wrapping this up for us, Ulrik. Glad you found the problem.

Mamiya C220. Light leaks?... Help!

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Japan Camera Hunter 120 Film Hard Case Olive - Holds 5 Rolls of 120 Size Film

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Mamiya C220. Light leaks?... Help!

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