Why One Might Prefer a Cloth FP Shutter.

ic-racer · Dec 10, 2022

Why One Might Prefer a Cloth FP Shutter.

The reason for starting this thread is to discuss experiences with shutter repair and mechanical camera longevity.

The following are some ideas based on observations in the 50 some years I have been using SLR cameras.

A few years ago, after getting more involved with mechanical SLR repair it was clear to me that not all mechanical SLRs are the same.

In fact, after studying repair literature on various cameras, I realized the benefits of the older horizontal cloth shutters.

In general, cloth FP shutters are integral to the body of the camera. For example, you usually can’t just take the shutter out as a unit. You have to disassemble all the pieces individually to ‘remove the shutter.’

Though this may seem a bad thing, the steps involved are similar across camera brands and the whole affair is well documented in the repair literature.

On the other hand, when manufacturers started installing metal, vertical shutters, these frequently came as an assembled unit from a shutter manufacturer (like Copal).
Although the specs of metal vertical shutters are the best in the business, the repair process for the shutters, in many cases, amounted to removal and replacement.

Now one might ask ‘where are all the new replacement vertical Copal shutters.’ And, of course there are none.

Clearly there are exceptions to these generalizations as some Copal shutters are well documented and some horizontal cloth shutters are nearly impossible to repair.

So, don’t discount cameras with cloth shutters, as they may indeed outlast the others.

Share your comments and stories.

gone · Dec 11, 2022

You may be right on the repair ideas. But it may depend on the camera. I normally used AF Nikons for my manual focus lenses (mostly the N8008s). Shutter repair was basically unheard of because I never, ever saw one w/ a shutter problem, or any problem. So if I had my choice between an easily repaired shutter or one that was difficult to repair, I wouldn't chose either one. I'd go with the camera that never needed a shutter repair.

guangong · Dec 11, 2022

Yes! I personally have never known a Nikon F or F2 that needed a shutter repair, unlike other brands such as Leica. I was told by a former Leitz technician that this was because Nikon shutter uses ball bearings, and Leicas ( except for wartime model C camerasv) did/do not. Somebody on forum should know the reality of this.

tokam · Dec 11, 2022

Don't overlook that cloth FP shutters on rangefinder cameras can also be subject to holes burnt in the fabric from sunlight. Won't happen with a metal FP shutter or with an SLR if the mirror is in the down position.

Tel · Dec 11, 2022

Happy to see this thread come up. I set myself the task of learning how to do curtain-shuttter repair and I find it pretty much as fiddly and often frustrating as leaf shutter repair, but in completely different ways. I picked up a bunch of parts-or-repair Minolta 35 Model II cameras for no other reason than they look like an ergonomic improvement over Leicas/Leica clones because of a hinged back door rather than a bottom-load. And you can get them very cheaply....

In the event, I didn't have to do a major stripdown (as you would with a Nikon F or F2). With the back open, you only need to remove eight or nine screws (depending on the year of manufacture) and the mechanism cover plate/film gate pops out revealing all the working parts. If you're deft with tweezers and small screwdrivers and fine brushes you can do curtain replacement without dismantling the camera any further than this. The hardest parts are gluing the new cloth onto the rollers in the darkest recesses of the mechanism (really only difficult with one end of the rear curtain) and aligning the front and rear curtains so that they operate together and don't allow light leaks where they overlap. I have made and discarded four or five curtain sets before I got the length of each perfect. (This was mostly because the camera I began with had curtains in complete tatters so I had no dimensions for reference.)

Getting materials to work with was problematic. I wanted rubberized silk material for the curtains--this stuff was easily available from Fargo/Micro-tools in California. They also sell curtain ribbons, but they only had 2mm ones and I wanted more robust ribbons, like 3mm or 3.5. Then there's the issue of the metal "lath" things on the leading edge of each curtain. These are very small u-shaped brass channels that fold over the leading edge of the curtain and pinch closed to keep the curtain rigid as it travels across the gate. In each case I had to re-use the ones I found; one set was complete toast and wouldn't lie flat so I bought a new curtain set (yes, you can still find them for sale) on ebay and carefully extracted the lath pieces from it. They were too long, so I cut them down and cut new slots for the ribbons--very fiddly work indeed. I found a good way to finish this part: I would glue the laths into place on the curtain/ribbon assembly, place the whole thing (carefully) between two metal blocks and tap with a hammer until they were perfectly flat. Anything at all sticking up (or down) will likely snag and cause the curtains to fail.

On the subject of failures, I found that Pliobond was OK for several iterations but failed to hold on several others. I attributed this to the age of my bottle of the stuff and got somewhat better results with a new one. But I saw in one of the youtube videos about Minolta 35 repairs (there are two) that Aki-Asahi recommends a Japanese adhesive called Super-X. I found that I could get this stuff from Amazon so I bought it and tried it. It seems to be a more aggressive adhesive than Pliobond and, when used correctly, makes a much more reliable bond. Aki-Asahi has a helpful page (in English) on his site giving instructions for using it, especially good since I don't read Japanese.

Ribbons were another problem. I had done curtain replacement on several Thornton-Picard curtain shutters a few years ago, which was good prep for this job if only because they are dimensionally cruder devices and easier to work with but a good lesson in the function of curtain shutters. By contrast, these Minoltas have very tight dimensions and tiny clearances between the moving parts of the curtains and using ribbons that are too thick (like the 1/8-inch ones that Fargo sells and that I used very successfully on a T-P shutter or two) simply didn't work on the Minoltas. In the end, on a particularly difficult one, I tried not using ribbons at all. I took one piece of curtain fabric and cut a rectangular hole out of it to make the curtain and "ribbons" in one piece. That worked superbly: I got very flat curtains with the absolute minimum of thisckness that worked together very smoothly.

All in all, this was a good exercise. As I have with leaf-shutter repairs, I've learned how to work more patiently and doggedly. When you get one of these things to fire properly, it's a kind of triumph and deserves a glass of your best whiskey.

Sirius Glass · Dec 11, 2022

tokam said:
Don't overlook that cloth FP shutters on rangefinder cameras can also be subject to holes burnt in the fabric from sunlight. Won't happen with a metal FP shutter or with an SLR if the mirror is in the down position.

It is not rocket science to keep the cameras away from looking directly aimed at the sun. Even lens caps can be used to prevent that. By the way a metal FP shutter will not survive a drop down the Grand Canyon either.

Sirius Glass · Dec 11, 2022

I have done minor repairs on the cloth shutter of my Graflex Model D.

ic-racer · Dec 11, 2022

Anyone repaired a vertical Copal Square-S in a Nikkormat?

Tel · Dec 11, 2022

ic-racer said:
Anyone repaired a vertical Copal Square-S in a Nikkormat?

View attachment 323922

Scary lookin' things. I've worked on a couple of Nikkormats but never went inside the Copal Square. Cutting up pieces of rubberized silk is more my speed, I guess.

guangong · Dec 11, 2022

Tel said:
Happy to see this thread come up. I set myself the task of learning how to do curtain-shuttter repair and I find it pretty much as fiddly and often frustrating as leaf shutter repair, but in completely different ways. I picked up a bunch of parts-or-repair Minolta 35 Model II cameras for no other reason than they look like an ergonomic improvement over Leicas/Leica clones because of a hinged back door rather than a bottom-load. And you can get them very cheaply....

In the event, I didn't have to do a major stripdown (as you would with a Nikon F or F2). With the back open, you only need to remove eight or nine screws (depending on the year of manufacture) and the mechanism cover plate/film gate pops out revealing all the working parts. If you're deft with tweezers and small screwdrivers and fine brushes you can do curtain replacement without dismantling the camera any further than this. The hardest parts are gluing the new cloth onto the rollers in the darkest recesses of the mechanism (really only difficult with one end of the rear curtain) and aligning the front and rear curtains so that they operate together and don't allow light leaks where they overlap. I have made and discarded four or five curtain sets before I got the length of each perfect. (This was mostly because the camera I began with had curtains in complete tatters so I had no dimensions for reference.)

Getting materials to work with was problematic. I wanted rubberized silk material for the curtains--this stuff was easily available from Fargo/Micro-tools in California. They also sell curtain ribbons, but they only had 2mm ones and I wanted more robust ribbons, like 3mm or 3.5. Then there's the issue of the metal "lath" things on the leading edge of each curtain. These are very small u-shaped brass channels that fold over the leading edge of the curtain and pinch closed to keep the curtain rigid as it travels across the gate. In each case I had to re-use the ones I found; one set was complete toast and wouldn't lie flat so I bought a new curtain set (yes, you can still find them for sale) on ebay and carefully extracted the lath pieces from it. They were too long, so I cut them down and cut new slots for the ribbons--very fiddly work indeed. I found a good way to finish this part: I would glue the laths into place on the curtain/ribbon assembly, place the whole thing (carefully) between two metal blocks and tap with a hammer until they were perfectly flat. Anything at all sticking up (or down) will likely snag and cause the curtains to fail.

On the subject of failures, I found that Pliobond was OK for several iterations but failed to hold on several others. I attributed this to the age of my bottle of the stuff and got somewhat better results with a new one. But I saw in one of the youtube videos about Minolta 35 repairs (there are two) that Aki-Asahi recommends a Japanese adhesive called Super-X. I found that I could get this stuff from Amazon so I bought it and tried it. It seems to be a more aggressive adhesive than Pliobond and, when used correctly, makes a much more reliable bond. Aki-Asahi has a helpful page (in English) on his site giving instructions for using it, especially good since I don't read Japanese.

Ribbons were another problem. I had done curtain replacement on several Thornton-Picard curtain shutters a few years ago, which was good prep for this job if only because they are dimensionally cruder devices and easier to work with but a good lesson in the function of curtain shutters. By contrast, these Minoltas have very tight dimensions and tiny clearances between the moving parts of the curtains and using ribbons that are too thick (like the 1/8-inch ones that Fargo sells and that I used very successfully on a T-P shutter or two) simply didn't work on the Minoltas. In the end, on a particularly difficult one, I tried not using ribbons at all. I took one piece of curtain fabric and cut a rectangular hole out of it to make the curtain and "ribbons" in one piece. That worked superbly: I got very flat curtains with the absolute minimum of thisckness that worked together very smoothly.

All in all, this was a good exercise. As I have with leaf-shutter repairs, I've learned how to work more patiently and doggedly. When you get one of these things to fire properly, it's a kind of triumph and deserves a glass of your best whiskey.

Great story!!

,

Tel · Dec 12, 2022

guangong said:
Great story!!

,

Thanks! Equal parts frustration and pleasure.

Tel · Dec 12, 2022

Tel said:
Thanks! Equal parts frustration and pleasure.

Edit: since no one asked, it was Balvenie

Craig · Dec 12, 2022

The flip side is the big cloth shutters in Graflex SLR's. I have a 4x5" Graflex and the rubberized coating on the cloth went hard and cracked, which prevent the shutter from moving. It's a roller shutter, has various slits to change the speed and is a piece of cloth about 6 feet long.

To repair it, I needed to soak it in lacquer thinner to dissolve the rubberized coating and gently scrap it off the cloth base and then recoat the cloth to make it light tight. Then wind up the shutter and put it back in the camera and re-tension the spring to give the right running speed. A set of metal shutter blades wouldn't have needed that kind of servicing.

KerrKid · Dec 12, 2022

Tel said:
Edit: since no one asked, it was Balvenie

I hope I never have to work on my shutters. I only have WT 101 in the house. Of course my shutters seem to last a lot longer since I've learn to wrap cameras around them before throwing them down the Grand Canyon.

chriscrawfordphoto · Dec 12, 2022

Craig said:
The flip side is the big cloth shutters in Graflex SLR's. I have a 4x5" Graflex and the rubberized coating on the cloth went hard and cracked, which prevent the shutter from moving. It's a roller shutter, has various slits to change the speed and is a piece of cloth about 6 feet long.

To repair it, I needed to soak it in lacquer thinner to dissolve the rubberized coating and gently scrap it off the cloth base and then recoat the cloth to make it light tight. Then wind up the shutter and put it back in the camera and re-tension the spring to give the right running speed. A set of metal shutter blades wouldn't have needed that kind of servicing.

Here's a guy who makes and installs new shutter curtains on Graflex cameras. His prices are HIGH, though. $716 for a Speed Graphic That includes installing it, but that can't be as hard as installing a shutter curtain in a 35mm camera, is it?

Craig · Dec 12, 2022

chriscrawfordphoto said:
but that can't be as hard as installing a shutter curtain in a 35mm camera, is it?

I don't have a basis of comparison, I've overhauled the Graflex and a large format Copal, but never a 35mm camera shutter. The Graflex wasn't bad to do, just time consuming and precision work.

Digital Wendy · Dec 12, 2022

Leaving slide film in my Canon in a hot humid climate created pinholes in the shutter curtains - or at least that's what a highly recommended technician in Singapore told me at the time. He traded in the Canon body for one with better curtains and the camera continued around the world with me for many more years. I would guess he eventually repaired the curtains on mine and repeated the process with the next, similar customer.
(Off topic: Same camera now has a problem with the metering on the shutter button and it's only [counts on fingers] 40+ years old! My youngster quite likes it so I have to decide whether to have it repaired again this time)

Tel · Dec 12, 2022

Craig said:
I don't have a basis of comparison, I've overhauled the Graflex and a large format Copal, but never a 35mm camera shutter. The Graflex wasn't bad to do, just time consuming and precision work.

I've done five Thornton-Pickard shutters before I tried the Minoltas. The Minolta shutters were so much smaller and the tolerances so much finer, and that was the frustrating part. The curtains had to fit perfectly in a narrow channel and overlap just the right amount in order to avoid a light leak as they travelled on the return (cocking) stroke. So the attachment of the curtains to the rollers on the right side of the camera had to be very precise. The left side is the tensioned rollers, and they could be adjusted in the tensioning process.

Tel · Dec 12, 2022

A question about the Graflex cameras: I once opened up an RB and it looked like the shutter was a continuous roll with openings of different widths to allow for different exposure times. The Thornton shutters are similar, but have a single opening and rely on the tensioned roller to set the travel speed and therefore the exposure time. The Minoltas, like a lot of 35mm cameras (or maybe all of them) use two shutter curtains with a geared delay on the second (following) curtain to set exposure time. Is this an accurate description or am I missing some information?

Craig · Dec 12, 2022

Tel said:
A question about the Graflex cameras: I once opened up an RB and it looked like the shutter was a continuous roll with openings of different widths to allow for different exposure times. The Thornton shutters are similar, but have a single opening and rely on the tensioned roller to set the travel speed and therefore the exposure time. The Minoltas, like a lot of 35mm cameras (or maybe all of them) use two shutter curtains with a geared delay on the second (following) curtain to set exposure time. Is this an accurate description or am I missing some information?

That's pretty accurate. The Graflex uses both varying width slits and different spring tensions to achieve the various shutter speeds. There is a plaque on the camera that gives all the possible shutter speed combinations of slits and spring tensions, so you can set the shutter speed you want.

Tel · Dec 12, 2022

Thanks; that makes good sense. Also explains why I never got my head around the Graflex shutter. I had a baby Graflex for a while but I always used the leaf shutter on the lens, never the focal plane shutter.

Sirius Glass · Dec 12, 2022

Tel said:
Thanks; that makes good sense. Also explains why I never got my head around the Graflex shutter. I had a baby Graflex for a while but I always used the leaf shutter on the lens, never the focal plane shutter.

What one can do with a focal plane shutter:

Open the lens with the 'T' shutter
Set the aperature
Insert film back
Remove the dark slide
Crank the focal plane shutter into position
Swear like mad
Go back to step one

Why One Might Prefer a Cloth FP Shutter.

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