Piece-by-piece lens

[The Muid]

Hi all,

I've been looking at different lenses, and I've worked out that it could be cheaper to buy an older lens with a broken or dodgy Compur shutter and a buy a seperate Copal shutter.

What I'm wondering is are these shutters interchangable with the lens barrels? Do I have to a shutter from the specific lens I buy?

I hope I explained it all well, lol. Thanks for your time and your help,



Diarmuid :cool:

[Gem Singer]

Changing lens elements from a Compur to a Copal shutter is not as simple as it appears to be.

Not only will you need to match the thread size, but also the final distance between the front and rear elements, as well as replacing the aperture scale.

A job for a trained expert.

[domaz]

It should work if you stayed with the same brand of shutter and size, no guarantees though with matching the distances.

[Steve Hamley]

Your best value for the money is a decent used lens of modern design ready to shoot. By the time you have the spacing checked and an aperture scale made, it isn't worth it.

Cheers, Steve

[Dan Fromm]

Interesting. And here I thought that, with the minor exception of press shutters' diaphragms' locations, modern (post-WWII) #0, and #1 Compur, Prontor, and Copal shutters' dimensions were standardized. Pre-WWII shutters are another matter, as are Rochester-made shutters (Supermatic, Rapax/Grafex, Alphax, Ilex).

But post-WWII lens cells that were delivered in a Compur #0 or #1 should be a direct fit into, respectively, a Copal #0 or #1.

Lens cells delivered in barrel are also another thing entirely. For example, I have a couple of tiny 150/9 Klimsch Apo Ronars in barrel whose cells aren't direct fits into shutter, also a small heap of pre-CEDIS Boyer lenses in barrel whose cells ought to be direct fits in #1s but, again, fit no known shutter.

I've had only one spacing issue; it seems that #00 Ilex Electronic shutters are threaded like #00 Synchro Compurs but are thinner. When I presented the problem to the late Steve Grimes he said "Oh. The shoulder problem." and machined out the Syncro-Compur so the cells would seat at the proper distance. #00s are somewhat a law unto themselves.

[Nathan Potter]

Hey Dan I'm no lens guru like many here but I had always thought that, as you state, #0 and #1 Compurs are of the same thickness as Copal #0 and #1. Nice that you reinforce my belief. But this brings up another question that might also have some bearing on the OPs' task. Some lenses have shims to adjust the spacing between the front and rear elements. I assume that this is done at the factory to meet performance specs. But I worry that when buying a used lens how do I know if the original factory spacer is present or was ever intended to be there? What's your take on this?

Nate Potter, Harrington Me.

[ic-racer]

Overall length of the lens can be measured and compared to the spec sheet for the lens.

You can adjust the shims to match the flatness of field to the working distance most frequently encountered.

A professional looking aperture scale can be made with a label maker or if you buy your shutter from SKGrimes, they can include an appropriate scale for an additional $50.

[Dan Fromm]

Hey Dan I'm no lens guru like many here but I had always thought that, as you state, #0 and #1 Compurs are of the same thickness as Copal #0 and #1. Nice that you reinforce my belief. But this brings up another question that might also have some bearing on the OPs' task. Some lenses have shims to adjust the spacing between the front and rear elements. I assume that this is done at the factory to meet performance specs. But I worry that when buying a used lens how do I know if the original factory spacer is present or was ever intended to be there? What's your take on this?

Nate Potter, Harrington Me.Nate, my take is that we all of us worry about problems we can't detect or correct. We're all a bit nuts, and "we" includes me.