Another Curtain Replacement

[Valkir1987]

I find most Russian camera's with metal strap cloth shutters with the vulcanized side of the curtains towards the lens. I did many replacements and I was wondering why. In my opininion its better to have the vulcanized side towards the film plane, so the most direct effect of light and possible heat on the rubber will be avoided.

The other reason I came up, was that it shows better when the back is removed. You see the fresh linen, instead of the grey vulcanite.

Just to share a thought. I would like to hear other opinions on this fact. 🙂

 

[sevo]

It is a matter of wear and leaking. If you put the rubber side outwards as the curtain is rolled up (where it will be film side on almost every FP shutter) the rubber is stretched relative to the fabric, which may put extra strain on it. Besides, all cameras put guides, covers and other parts that touch the shutter cloth on what they assume to be the fabric side, as the fabric is far more rub proof.

Aki Asahi also sells a double sided fabric curtain material - personally I tend to use that wherever the strength permits, as it is less prone to wear and works either way.

 

[Valkir1987]

Thank you for your valuable answer. I will do so from now on.

 

[fidget]

Every FSU camera that I have has the fabric side facing the lens, many of these have the original curtains.

 

[wolves3012]

Every FSU I've seen has the rubber on the film-side, just as fidget notes. As for bending the cloth or rubber side, I can't see how it makes a difference in practical terms. I find that the very old and the very new examples are the ones that fail. This suggests to me that later models had poorer quality material.

+1 for the double-fabric Aki Asahi material, I've done several with that and it's of excellent quality.

 

[sevo]

Every FSU I've seen has the rubber on the film-side, just as fidget notes.

A FED-2 is my only cloth-curtained FSU - it has the same rubber-towards-lens arrangement as every German or Japanese camera I ever handled. If FSU cameras of some type or generation had the rubber towards the rear, it might be worth while figuring out which ones and why.

They might have had a period where their curtain cloth just happened to roll rubber outwards. Unless the cameras needed a modification for that to work (unlikely given that FSU cloth shutters evolved from the unguided Leica shutter), it could be replaced with conventional cloth in a repair.

 

[wolves3012]

Ok, so I need to check my "facts" in future! Disregard the post above. All of my *bottom-loading* FSUs have the rubber on the film-side. All the other cloth-shutter cameras I have (including the Leica IIIC, Zenith and Minolta) have the rubber on the lens-side.

Maybe it was done to reduce the chance of fingers or film damaging the rubber when loading? On a bottom-loader, you can't touch the back. On others, you're less likely to touch the front. All I can think of anyway.

 

[sevo]

Maybe it was done to reduce the chance of fingers or film damaging the rubber when loading? On a bottom-loader, you can't touch the back. On others, you're less likely to touch the front. All I can think of anyway.

Maybe. Or that shutter design has some front side guide, baffle or whatever that can touch the moving cloth - you'd want to avoid that on the rubber side. In any case, if they did it consistently, there could be a relevant reason for it, and it will be advisable to stick to it in repairs.

 

[fidget]

Maybe a change in style? The only bottom loaders I have now are a Zorki 5a and a 5b. The 5b has rubber side on the film face. I will check the 5a when I next see it. These have those wonderful (and I guess original) curtains that have the cloth wrapped and stitched around the lath.