Light leak or processing fault.

[rossawilson1]

On my Leica M6 c41 negs I'm getting more and more what appear to be light leaks only around the sprocket holes down one side of the film.

There's a discoloration around the edge of the holes leaking into the actual frame by a few millimeters, in a manor that looks like a light leak. However, I process these negs myself and I'm not sure if it's a processing fault perhaps where the developer isn't properly covering all the film around the sprocket holes.

Anyone any ideas on this? Ever had any problems with sprocket hole light leaks? Does my M6 need a CLA?

 

[Ian Grant]

Sounds very odd, you really need to post a scan. Have you checked the light seals on the back, that's the only place you could get a light leak. Seems very unlikely.

Are you sure it's not contamination from your spiral. Give it a good clean, soak it in washing powder, use an old tooth brush to scrub the slots the film threads into, then rinse it and give it soak in strong blaech (Domestospor similar) finally wash it well.

Ian

 

[JBrunner]

I agree with Ian. It is a fairly unlikely place for a camera leak, although you might check the seals in the area of the take up spool. More likely a leak in the tank lid, a developing issue, or contamination as Ian said. Posting a scan would be most helpful.

 

[John Koehrer]

It does sound like processing to me too.(big whip).
Are you using sufficient solutions to entirely cover the film in the tank? and is it always the same edge of the film, top or bottom? Would it change if you put the reel in the tank "upside down"?

 

[rossawilson1]

I'm thinking the reels too now.. here's a picture:

 

[Ian Grant]

It's not fogging that's for sure, it might be your agitation. Or is it a Paterson tank, sometimes the spirals ride up the columns and your suffering from insufficient development that top edge.

Ian

 

[rossawilson1]

It is a Patterson tank, but I'm not inverting, only using the twiddle stick. How do you mean insufficient developing I can't see what you mean?

I think I'll just use a different reel, I've got loads and this was an old one anyway. Maybe it's got loads of stabilizer on it.

 

[Herzeleid]

It is the stick, that happened to me too, and took a lot of experiment to find it out. Just try it once without stick, try the inverting method. I had the same problem with an AP tank and Paterson tank.
I use the stick for first agitation, right after pouring the developer it dissolves the bubbles efficiently then I took it out then I close the lid and do the inverting. I use the stick in the fixation process it does not cause any problems at that stage. I can post a neg scan if you like to see one.

 

[rossawilson1]

That's okay Herzeleid, I'll take your word for it and try the inversion method next time. Thanks for saving me a lot of trouble, I appreciate it!!

 

[Herzeleid]

Hopefully this solves the problem. I don't know why it happens though, some people have no problem with it.
Your welcome

 

[Ian Grant]

The stick makes sense because it's caused by the agitation. I've always used Paterson tanks with inversion processing of Colour and B&W. If you stir water you get a vortex, the liquid level dips in the center and rises at the edges, this can happen when you use the stick method of agitation.

The reason I said insufficient developer was because there's clearly under development around the sprocket holes, but Herzeleid has almost certainly identified your problem. With inversion agitation a lot of the Paterson tanks use a collar to stop the reel shifting up the column, if you haven't got one choose a spiral that's reasonable tight fit on the column, they do vary a bit.

Ian