horizontal scratch and back plate

[flo617]

Hello,

I recently purchased a Ricoh 500G. Everything is functional and it should have been my perfect little camera to take everywhere.

Except... I developed my first film yesterday (Hilford HP5 400) and I noticed several thin horizontal parallel scratch marks, evenly spaced from top to bottom (think prison bars), and running the whole length of the negative. They are located on the back of the film. Other than that, the images look fine. I will scan them later today to see if the scratches appear on the scanned image or not.

I did a few experiments, wasted a few films and found that the culprit is the back plate. When I take the pressure plate out, no problem. When I put it in, the marks appear on the undeveloped film as I take dummy shots and advance the film.

The back plate seems fine though, no apparent pollution, it is totally smooth and I washed it with a bit of distilled water to be sure. I'm no expert but the pressure does not seem to be too strong either.

Any suggestion as to how I could address this issue? This is a truly loveable camera in great shape otherwise and I would love to be able to take clean shots with it.

Thank you,

Florent

 

[Corto]

Show us some samples please.

 

[Derrel]

Does the back have a dent in it??? It would seem like it might, since the pressure plate springs are pretty simple, and have been worked out by the manufacturer...I mean, that is NOT rocket science...I suspect maybe the camera's back has been dented through rough handling. I am not thinking of a small depression or crater, but rather a broad, sweeping inward "bend" or "displacement" of the central part of the back.

 

[compur]

The 500G has a roller just to the left of the pressure plate. Have you checked that? Is it clean and does it rotate freely?

That camera also has a huge amount of light seal foam on the film door which would surely need replacement if not done already. Has that been done? Bits of dried out foam can scratch film.

 

[flo617]

The foam has been redone (although I think I'll end up re-re doing it)

The roller has been cleaned and looking at how the marks get done, it seems they happen before the film reaches the roller.

I have a pic to upload but somehow the website does not let me.

 

[flo617]

OK here it is:

http://www.thephotoforum.com/photos/data/500/medium/marks.jpg