Mystery Puncture

[Shootist]

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When I used a lens to burn a piece of gaffers tape, it did not produce sharp edges. Why don't you try using the lens to burn a similar piece of cloth and see for yourself if you can duplicate the holes?

 

Well maybe not sharp but possibly cleaner, less ragged, edges. Not sure never burned a hole through a shutter or anything else, that I can remember.

[rob139]

Sigh, suggest you need to read the instruction booklet that came with the M or Barnack... and I don't think there are any bits likely to migrate unto front face of curtain. The scratch marks are characteristic in position and damage from sun burn.

 

Well, if you say so. Something loose does not neccesarily mean it has to come from the camera itself. Could have been film, rubble from a lens, or something from the toolshed.

And I agree it is not likely, but is it impossible?

 

I have never seen marks form the sun that look like the scratches on this shuttercurtain. These scratches could have been made at a different moment, of course. One cannot say for sure that all the marks were made by one single thing, be it the sun, or a shard of something.

Anyway, if it was my MP I would make absolutely sure that these marks were not made by something drifting in the camera.

 

If it was the sun, however, one should be able to determinate when this has happened. I take it that there was film in the camera, so at a certain stage, this hole had to appear on the film as a white spot, somewhere during daytime, and outside, right? That won't be too difficult to check.

 

Good luck with the camera, hope the repair turns out right.

 

Best, Rob

[AlanG]

I have never seen marks form the sun that look like the scratches on this shuttercurtain. These scratches could have been made at a different moment, of course.

 

He said the large "scratch" was on the curtain initially.

 

Here is what holes burned in gaffers tape look like. This only took about two seconds with a 50 f2 lens. I think a rubberized shutter curtain would burn even easier. It would be pretty easy to melt the rubber in an arc or a line. There have been numerous reports of people burning their rangefinder shutters over the years. I think a foreign object caught in the shutter would have to be pretty large and sharp to cut through it rather than just make the cloth bulge around it. And I don't see how something that large could get in there in the first place. But perhaps it is possible. Or someone poked it with something. Which he said didn't happen. On the other hand, a burned shutter is a pretty obvious and likely conclusion. (Besides shutterbugs of course.)

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[rob139]

Well, I guess that's it then. Blame it on the sun. But why spoil a perfectly good piece of gaffertape???

 

 

He said the large "scratch" was on the curtain initially.

 

I'm sorry Alan, I can't find where he said that.

 

Best, Rob

[AlanG]

"Here are some pictures of the damage (the black vertical line on the metering patch has been there since new)." Sorry, I guess he was not referring to the large mark below the metering patch. But that and the rest look like burns and melted rubber to me. I think the arcs and irregularities are from moving the camera slightly as the sun was melting the rubber on the shutter. This could happen pretty quickly with a fast lens, strong sunlight and the image focused on the shutter.

 

I used a small piece of gaffers tape but my first impulse was to burn the broken shutter on an old Pentax of mine. The first Pentax on my shelf that I looked at doesn't have a shutter curtain in it any more. I don't know what happened to it, but it is such an old model that they only wrote "ASAHI OPTICAL Co. Japa" on it without the "n." So I've been saving it. And that 2 inch piece of tape can still be useful even with holes in it! Call me cheap.

[marcusperkins]

OK All, sorry for the late reply - been very busy.

 

The damage to the shutter was in fact caused by 'Sun Burn', so thanks for all your comments and advice and in some cases jokes.

 

The holes were too big to fix, so I had a new shutter cloth fitted.

 

Marcus