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View Full Version : When is a #1 shutter not a # 1 shutter



tonyowen
19-Dec-2017, 04:39
I'm confused regarding the different types of #1 rimset shutters available.
I see #1 copal, #1 synchro-compur, #1 copal press shutter, #1 copal (polaroid) shutter, #1 German press shutter
Do they all have identical lens cell threads [M40 front, M36 rear]?
Are they all the same thickness?
Do they all have flash sync?
I know the speed settings can be /are different.
What do I need to be aware of, regarding problem areas, incompatibility etc?
regards
Tony
ps I've looked at Dan Fromm's sticky, but it does not seem to answer my fundamental question

Dan Fromm
19-Dec-2017, 05:38
All of the shutters you named that I'm acquainted with are made to approximately the same specification.

I don't know what a #1 German press shutter is, could you be more specific about it?

Copal and Compur #1s have the same threading and tube length.

Copal #1 Press shutters -- you forgot the Prontor -- have the same tube length and threading as the #1 cock-and-shoot but have the diaphragm set back a little (= front tube longer, rear tube shorter). As a result, rear lens cells that go deep into the shutter may contact the diaphragm leaves. Examples, none large format, 60/5.6 Konica Hexanon for Koni-Omega, 80/2.8 Planar for Graflex XL. An LF example, 210/5.6 Fujinon W (late type with engraving on the lens barrel, not on the trim ring). This isn't a problem with most lenses.

Press shutters -- you forgot the Prontor -- have top speeds of 1/125. Cock-and-shoot Compur/Copal #1s have top speed 1/400.

Copal-Polaroid shutters are all press shutters. I haven't measured #0s, have measured #1s. Their tube length is, IIRC, 20.2 mm. The standard is 20.0. Not sure why Polaroid specified 20.2 mm tube length, possibly to discourage people from repurposing their shutters.

The sticky doesn't have the answers, you have to follow the links.

Pere Casals
19-Dec-2017, 05:40
Press versions are `self-cocking´ (I it is a shutter which is cocked whilst pushing the release knob.)

"Today the thread size for the lens cells of all 0, 01, 1, 3 shutters from Copal, Compur, Prontor, Noble, Horseman, Rollei and Seiko are identical as are the thread sizes to attach them to the lens boards. Old shutters from various manufacturers varied the sizes but today they are standardized as are the lens cell thread sizes."


IMHO you here have some good information:

http://www.largeformatphotography.info/shutters.html#modern

http://camerapedia.wikia.com/wiki/Prontor

http://www.skgrimes.com/products/new-copal-shutters/pressshutters

Regards

pd: just after posting I saw it was answered yet... so this is redundant.

Jim Jones
19-Dec-2017, 07:14
. . . Copal #1 Press shutters -- you forgot the Prontor -- have the same tube length and threading as the #1 cock-and-shoot but have the diaphragm set back a little (= front tube longer, rear tube shorter). As a result, rear lens cells that go deep into the shutter may contact the diaphragm leaves. Examples, none large format, 60/5.6 Konica Hexanon for Koni-Omega, 80/2.8 Planar for Graflex XL. An LF example, 210/5.6 Fujinon W (late type with engraving on the lens barrel, not on the trim ring). This isn't a problem with most lenses. . . .


In at least some lenses, the position of the diaphragm along the optical axis does make a noticeable difference in a lens' optical performance, even if the lens does otherwise fit and function in a shutter with an inappropriate diaphragm position.

tonyowen
19-Dec-2017, 09:27
Thank you all
Regarding the query over the 'German shutter' please see attached.
As for Prontor - I read somewhere that they were no longer available or serviceable.
Does the potential problem of a diaphragm position on the Copal #1 press shutter apply to the Copal-Polaroid shutter?
The lens cells I'm thinking of using are Schneider Symmar 180/f5.6. Does anyone care to comment on the how the rear cell might be affected by the 'offset' diaphragm or the image quality by the extra 0.2mm should the Copal press or Copal-Polaroid shutter be used?
regards
Tony
172971

Dan Fromm
19-Dec-2017, 09:27
Jim, I think it depends on the lens. A lot. Skgrimes says:

Most of the specifications are the same as the ordinary shutters except:

Top speeds are slower: fastest speed is 1/125 sec
#0 Minimum iris opening is 2 mm on the press, 1.5 mm on regular.
#1 Minimum iris opening is 2.5mm on the press, 2 mm on regular.
The iris is about 0.75mm farther back in the shutter.

Dan Fromm
19-Dec-2017, 09:39
Thank you all
Regarding the query over the 'German shutter' please see attached.
As for Prontor - I read somewhere that they were no longer available or serviceable.
Does the potential problem of a diaphragm position on the Copal #1 press shutter apply to the Copal-Polaroid shutter?
The lens cells I'm thinking of using are Schneider Symmar 180/f5.6. Does anyone care to comment on the how the rear cell might be affected by the 'offset' diaphragm or the image quality by the extra 0.2mm should the Copal press or Copal-Polaroid shutter be used?
regards
Tony


Tony, a press shutter is a press shutter.

I thought I told you that normal standard non-Polaroid Copal Press #1 shutters have the standard tube length. 20.0 mm. Copal-Polaroid #1 Press shutters (all Copal-Polaroid shutters are press shutters) have, IIRC, 20.2 mm tube length.

My friend Eric Beltrando and I have discussed the implications of putting a modern plasmat type taking lens in a Copal Polaroid shutter. Eric wrote a ray-tracing program, visit dioptrique.info to see how he's used it. He tells me that with these lenses a tube length that differs from spec by a small percentage of focal length -- an 0.2 mm error is 0.36% of 180 mm -- should have only a slight effect.

Production of Compur, Copal and Prontor shutters ceased some years ago. The only new ones available are new old stock and very expensive.

That German Press Shutter is a Prontor. I have no idea why the seller is being cute about what it is, he should know.

Tracy Storer
19-Dec-2017, 11:45
TAKE NOTE: Some of the #1 Press-type shutters, particulalrly "Polaroid" badged ones, may not have diaphragm apertures since they took enlarging type lenses which had their own integral apertures.

Pere Casals
19-Dec-2017, 12:32
visit dioptrique.info

This is a very interesting site ! this is the heliar: http://dioptrique.info/OBJECTIFS17/00812/00812K.HTM

An impressive job done there...

Anyway it is clear that the diafragm has to move substantially to have an impact, what I understand is that when stopping we crop a set of rays that are better corrected than the average when wide open, so diafragm position in the optical axis has to be moved "relatively a lot" to take a substantially different crop of rays.

Jim Galli
19-Dec-2017, 12:53
Early rimset Compur #1 with three actuating blades do not have the relief at the top of the thread area. Threads go all the way out. Some lens barrels are machined so that relief is necessary for the proper fit. ie. you can't put G-Claron cells in the early shutter, etc.

The one in your picture looks like the Polaroid MP4 and MP3 ones that did not have aperture blades, so they're kind of useless. 75mm Tominon has itty bitty aperture, like 15mm max. Tominon 127mm has a restrictive aperture also. You can't get to f5.6 on a 210mm lens. These are all lessons that it cost me money to learn. The cheap solution is to buy factory set lenses in their original shutters, or if like me, that simply won't do either, wean yourself from shutters and learn to use a Packard shutter. Most of the stuff in my pages is done that way. Not all, but much.

Dan Fromm
19-Dec-2017, 13:22
Jim, I wasn't sure the thing had a diaphragm so I found the ebay listing. If you're interested, search for "German press shutter." The listing says:


A standard sized shutter for use with a lens elements. This is a ‘press’ shutter, so it is cocked and released with a single press of the shutter release cable. Shutter has speeds from 1/125 to 1 second, plus B. There is an aperture control on this lens. There is an aperture scale indicating f4.5 to f22. This item has just been professionally serviced. It is supplied with an extended six month warranty.

The listing's shot of the shutter's rear shows what I think is a disc that limits the opening. No idea whether it can be removed easily.

Jim Galli
19-Dec-2017, 16:27
Jim, I wasn't sure the thing had a diaphragm so I found the ebay listing. If you're interested, search for "German press shutter." The listing says:



The listing's shot of the shutter's rear shows what I think is a disc that limits the opening. No idea whether it can be removed easily.

Those were the industrial shutters made by Prontor. I do remember some hang up but I can't remember what it was. Maybe the aperture too close to the back or some other limiter that was in the way.

Jac@stafford.net
19-Dec-2017, 18:36
The listing's shot of the shutter's rear shows what I think is a disc that limits the opening. No idea whether it can be removed easily.

Ain't nothing that precision needle-nose pliers can't fix.