Canonet Scratches

[KRC]

I got one of these recently -- the final version. It appears to be in fine shape and was CLA'd by a now-defunct camera store in Boise sometime in the past. Meter works.

3 rolls now I have fine horizontal scratches on the back of the film. There must be 10+ of them, some heavier than others. Sometimes it looks like a smear. For a frame or two it will be OK. Film is bulk rolled Tmax 400, but I've tried commercial loads and it does it on those too. I develop with Nikor stainless tanks, something I've been doing since about 1969 without issues.

I thought there must be something rough on the pressure plate. No, it is smooth as can be. I see nothing in the film path that can do this other than the pressure plate. I noticed the light seals were kind of gummy, and I replaced those thinking that the back would be a bit tighter and put more pressure on the film with collapsed seals. It made no difference. I can't see a way to adjust tension on the pressure plate, but there is an area in the camera back where I could shim the pp a little to have it exert less pressure.

Any suggestions would be appreciated. I've searched for similar threads, the best one is now a dead link.

Thank you.

 

[Sonnar Brian]

I had this happen with a Retina IIa- and found a burr near the take-up spool on the wind side. Another camera- pressure plate had a burr.
All I can suggest- feel the path the film takes with your finger, same with the pressure plate. Check that the rollers for the quick-load mechanism are moving freely, not gummed up. I just looked at my parts Canonet- the rollers move along the back of the film.

 

[Tim Murphy]

I got one of these recently -- the final version. It appears to be in fine shape and was CLA'd by a now-defunct camera store in Boise sometime in the past. Meter works.

3 rolls now I have fine horizontal scratches on the back of the film. There must be 10+ of them, some heavier than others. Sometimes it looks like a smear. For a frame or two it will be OK. Film is bulk rolled Tmax 400, but I've tried commercial loads and it does it on those too. I develop with Nikor stainless tanks, something I've been doing since about 1969 without issues.

I thought there must be something rough on the pressure plate. No, it is smooth as can be. I see nothing in the film path that can do this other than the pressure plate. I noticed the light seals were kind of gummy, and I replaced those thinking that the back would be a bit tighter and put more pressure on the film with collapsed seals. It made no difference. I can't see a way to adjust tension on the pressure plate, but there is an area in the camera back where I could shim the pp a little to have it exert less pressure.

Any suggestions would be appreciated. I've searched for similar threads, the best one is now a dead link.

Thank you.

Dear KRC,

You can also try tracing the film path with a lint-free lens cleaning cloth or a piece of your wives' old stockings if they a choice, to feel for snags and burrs.

If anything catches, you'll need to investigate further for the cause.

Regards,

Tim Murphy 🙂

 

[KRC]

The rollers seem to spin freely.

The damage looks like what you get when you try to clean a windshield with an old dried out squeegee. Kind of smear with lots of lines in it.

There are two shiny slot head screws that appear to be the stops for the plate with the rollers on it when it swings over as I close the camera. I'm wondering if backing those out slightly would help. As I said, the pressure plate itself, including the edges, seems very smooth. The number of small scratches seems inconsistent with there being a snag or two.

 

[ChrisPlatt]

Suggest you look carefully at the proprietary "quick load" mechanism. Something may be bent.

Chris

 

[Mackinaw]

I noticed film scratches on an old quick-load Canon I once had. It turns out the rubber take-up pads on the quick-load mechanism had hardened over the years, and the film wasn't properly loading onto the take-up spool. I dabbed a bit of rubber cement on them, and the problem went away.

Jim B.