Polaroid shutters: Are they bad?

[Mark_3632]

I was told that these were good but no more was said. Now I am looking at a lens that has one. I had a lens with polaroid shutter but a five foot fall to the ground ended the shutter's life. Worked fine up until then. Why don't people like them?

[brook]

I think most are Prontar single action shutters that were on Poloroid copy cameras. They are just fine, unless you drop them or hit em with a hammer or something.

[John Kasaian]

Some are Prontor, some are Copal. Size "0" and size "1" Limited shutter speeds but for me thats a non issue. All the ones I've seen are double action "press" types(no cocking) Works fine for mounting G Claron barrel lenses up to 305mm(size 1) or a 150mm(size 0)

[Alan Davenport]

Why don't people like them?

For the same reason they won't buy a Caltar lens, yet they will happily shell out twice the bucks for a used Schneidenstock that is the exact same lens. Don't complain too loudly, if they start buying these things it will drive the prices up!

[Ernest Purdum]

The MP-3 and MP-4 shutters are intended for use behind small barrel mounted lenses and therefor have no diaphragms. They are great for their intended use but are not suitable for mounting cells into.

[Dan Fromm]

Yes, Ernest, but CU-5, DS-34, DS-39, and who know what other Polaroid shutters have diaphragms. Jim Galli has made a second career out of putting, e.g., G-Clarons in ex-CU-5 shutters for resale.

The thing to be aware of when hunting one of these shutters is that size (in mm) of the maximum aperture depends on the lens in the shutter. For 127/4.7 lenses, the max is 27 mm; for 105/4.5, 23 mm; for 75/4.5, 17 mm. I gather that Polaroid didn't pay for more than was needed.

Jim learned all this the hard way. And now we understand why he offers so many 127/4.7 Tominon cells, and no other Tominon cells.

Also, 17/4 and 35/4.5 Tominons were offered for the CU-5. These lenses are front-mounted on diaphragmless shutters. It isn't safe to buy just any old CU-5 lens with shutter in the expectation of putting, e.g., a G-Claron in it.

[Bob Fowler]

"I think most are Prontar single action shutters that were on Poloroid copy cameras. They are just fine, unless you drop them or hit em with a hammer or something."

For what it's worth... Self cocking shutters are double action, not single action. As with handguns, a single action requires a separate cocking action by the shooter, double actions cock and fire with one movement.

Most of the more recent examples of Polaroid shutters are Copal, though there are a lot of Prontor examples floating around out there. Some do not have an iris and are only good for attaching lenses still in barrels. Others have size 1 lens cell threads, but have an iris that doesn't open any larger than a size 0 shutter.

In answer to the original question, I've had a few of these shutters and was not impressed by the build quality. Whenever possible, I remount into a Synchro Compur or newer Copal shutter as soon as possible.

[brook]

My mistake, double not single action.