beginners question on copals

[toprock03]

ok - sorry for the entry level question. i am brand new to film and LF

I have a copal 1 210mm sinaron s 5.4 lens.

i am looking for something wide - i think around a 90mm. if i buy something that is a different copal are the lenses interchangeable? I think i'll need a new lens board, but aside from that can i swap them out without adjusting?

thanks so much in advance

[Ari]

No; Copal 1 is the shutter size (there's 00, 0, 1 and 3).
If you want to swap lenses, best to try with lenses from the same size shutter, but that's no guarantee either, as spacing varies from lens to lens.

[toprock03]

No; Copal 1 is the shutter size (there's 00, 0, 1 and 3).
If you want to swap lenses, best to try with lenses from the same size shutter, but that's no guarantee either, as spacing varies from lens to lens.

Thanks for the quick reply -

i assume most sell the lenses with the shutter correct? if that is the case what is the advantage to staying with a certain copal? do most keep them in their own lens board so they can just swap them out?

So if im looking for a 90mm lens do you recommend staying with copal 1?


thanks again

[Kevin Crisp]

There is no advantage really to staying with a certain shutter size. Copal 0, 1 and 3 are shutter sizes of copal shutters. Compur shutters also come in those sizes, and more. Generally if you have a 210 mm lens mounted in a shutter, you leave it in the shutter, and your wide angle next lens will have its own shutter. Could be a copal 0, could be a copal 1; it doesn't matter. But you need a lens board to fit it, unless the two lenses have the same size shutter and you don't mind taking one lens off the board and putting the other on. Since lens boards are cheap, get a second board so you can quickly swap out lenses.

Far more modern lenses are sold in shutters than not, vintage lenses not so much.

If you start putting elements of a 90mm lens in the same shutter you use for the 210mm, your aperture scale will definitely be off and there may be very thin spacers that you may lose when swapping out lenses into just one shutter.

Hope this answers your questions.

[BrianShaw]

Generally (most of the time, with great exception) each lens will have its own shutter, and each lens & shutter will have their own board. It is just too hard to attempt economy by swapping out these parts.

90mm lens will generally have a smaller shutter, like a Copal or Compur 0.

[Dan Fromm]

No; Copal 1 is the shutter size (there's 00, 0, 1 and 3).
If you want to swap lenses, best to try with lenses from the same size shutter, but that's no guarantee either, as spacing varies from lens to lens.

Are you sure? I thought that lenses' mechanical designs conform to the shutter standards.

[Dan Fromm]

if i buy something that is a different copal are the lenses interchangeable? I think i'll need a new lens board, but aside from that can i swap them out without adjusting?

Not without considerable expense. Look here http://www.skgrimes.com/products/new...standardcopals for the specifications.

The general rule is one lens, one shutter. The big exception, and it makes no sense for you, is lenses in barrel mounted in front of a shutter. In that situation, one shutter, many lenses gives the best economics.

[Cor]

Lenses and shutters can sometimes be swapped. The important thing is that the overall length of the lens stays exactly the same. Say you have a barrel mounted 240 mm G-Claron, it will fit directly into a Copal 1, or as I did in one of these MP4 Polaroid shutters: the overall length was exactly the same. One caveat though is the exact position of the aperture, it seems to be at a slightly different position in a Polaroid Copal versus a standard Copal.

Lens gurus can chim in, but I never noticed a difference, but I only contact print my 8*10 negatives..oh and I have re mounted a older 150 Symmar from a old Compur to a Polaroid Copal Press for 4*5, and did not notice sharpness issues in enlarging 4*5 negatives which could be traced back to the shutter.

Oh and you have to re-calibrate the aperture plate.

Best,

Cor

[Dan Fromm]

Say you have a barrel mounted 240 mm G-Claron, it will fit directly into a Copal 1, or as I did in one of these MP4 Polaroid shutters: the overall length was exactly the same.

Interesting. But the MP-4 shutter has no diaphragm, so isn't very useful.

One caveat though is the exact position of the aperture, it seems to be at a slightly different position in a Polaroid Copal versus a standard Copal.

Look here http://www.skgrimes.com/products/new-copal-shutters at Press and cock-and-shoot shutters. The diaphragm is located closer to the back of the barrel in all Press shutters, including Prontor Press shutters, than in the same size cock-and-shoot shutter. This can be a problem when trying to use a Press shutter with a lens whose rear cell goes deep into the shutter.

You didn't mention that the barrel of the Copal Press shutters Polaroid sold with Tominon lenses in them for, e.g., the Polaroid CU-5 is longer than standard.

[tlitody]

When you are out in the field it simply isn't practical to start moving lenses between shutters and lens boards.
Mostly people have a lens pre-mounted on a shutter which is pre-mounted in a lens board so that changing lenses means changing lens, shutter and lensboard combined.

Note that lens boards are cut for a specific shutter size, so if you have a lens with a copal 1 shutter then you must have a lens board with a copal 1 size hole cut in it. You can't swap shutters between lensboards of the wrong size hole.

The size of shutter varies because of the requirements of lens aperture size so the longer the lens focal length and the wider the max aperture of the lens, the bigger the shutter size tends to be.