Drop-in Shutter - Lens Combos

[John Downie]

I have heard that the G-Claron 150mm will drop into a Copal 0 with no extra work, making the retrofit cost effective. Do people know of other such pairings where a cost-effective mating might be made?

TIA

[Kevin Crisp]

G Claron 210, 240, 270 and 305 into Copal 1 or a Compur 1. Always check the distance with calipers to be sure, but I've done each of these and they come out the same to the 0.001".

[Ernest Purdum]

The 355 G-Claron fits a Copal (or recent Prontor or Compur) #3. The older 305mm G-Clarons also need a size 3 shutter. You can tell the older ones by the filter size. They take a 58mm filter, while the later ons need a 67mm.



At least some of the Repro-Clarons directly fit into shutters, and it's worth checking the Componons and Comparons (not Componars) as well. Schneider has been doing this for some time. The only other Schneider lens that I have personally experienced fitting into a shutter was a big convertible Symmar that screwed right into a Compound. Some Voigtlander lenses also are direct fits, as are at least some DB mount Sinarons. Some Wollensak lenses are threaded to the same dimensions as their shutters, but the spacing may differ. It's easy for a machinist to measure the thickness of a shutter against that of a barrel mount. Per the S.K. Grimes website, the 270mm f9 Computar is another direct fitting lens.



Here are the thread sizes of modern shutters: #0 - 29.5mm Front & Rear. #1 - 40mm Front, 35mm Rear. #3 - 56mm Front & Rear.



The size three shutters are so expensive that it might be no economy to buy a lens with the idea of having it mounted in one. In buying a used Copal, an all-black (later) model is worth more than one with chrome trimming, but both are fine shutters. I personally like self-cocking shutters, but for some reason their diaphragms are not quite in the same place as the cocking type. This can cause a problem.

[John Downie]

There is a Vario shutter on ebay that the seller says is the same size as a Copal O - if so, it seems a good buy. Is the mount the same? (Just leave me one)

[Ernest Purdum]

First an apology. I perpetuated a typo from a dealer's catalogue rather than going to the source. The rear thread of a Copal #1 is 36mm, not 35mm. Regarding the Vario, they were made in a variety of sizes and this one probably is the same size, but it is not a very good shutter. They were intended by Gauthier as a budget model for low to moderately priced amateur cameras.

[John Downie]

If one used it primarily on "B", is the Vario ok, or is it a reliability issue?

[Michael S. Briggs]

Lens cells from barrel mounts of several focal lengths of the Computer/Graphic-Kowa lenses may be direct fits into shutters. Unless you can measure or test the cell threads, it is a gamble, because some versions are direct fits and others are not. Most of the focal lengths go into the Copal 3S shutter, which has different threads from the more common Copal 3 version.

[Ernest Purdum]

To use primarily on Bulb, the Vario should be O,K..

[Arne Croell]

Most of the f/9 Docter Germinar W (not(!) Apo-Germinar W) process lenses will fit, too. The 150mm fits in a Copal 0, the 210, 240, and 305mm fit in a Copal 1. The front cell of the 355 also fits a Copal 3, but the back cell has a smaller thread diameter and needs an adapter. They are similar to G-Clarons but a design from the mid-1990's and multicoated. Docter introduced them shortly before their bankruptcy, so not many were made.

[Øyvind Dahle]

Ernest Purdum wrote: "The older 305mm G-Clarons also need a size 3 shutter"

I have read that it will fit a Compound #2. Mine has a 62mm front-diameter and 58 on the back, and will not fit a Copal #1 !

[Jon Wilson]

I have a 210mm Congo, 240mm Kowa, 305mm Kowa, 360mm Congo all of which are a direct fit in a copal 3s shutter. However, check other forum threads, but some of the Kowa barrel lens do not directly fit a copal3 or 3s shutter. I may have just been fortunate. I have come across three different "styles" of copal 3s shutters with only the newest one actually marked copal 3s. The other two are older styles of copals which are marked only as " copal 3." If anyone is interested in serial numbers on these different lens and/or copal 3s styles and a better description of each, then let me know and I will pull them out.