Finding #3 shutter for G-Claron 355mm f/9

[lassethomas]

My newest acquisition just arrived. A G-Claron 355mm f/9, in a very nice condition. And acquired for not much more than a song.
Barrel mounted though, so I have to find a shutter, to fit it for my 4x10 Chamonix.

I just assumed that I can move the front and back cells to a #3 shutter and all will be well. (As I've done with my 150, 210 and 240 Clarons, that I also got barrel mounted).

But how to get a #3 shutter (#0 and #1 shutters I have plenty to swap around)?
The first thing that comes to my mind is buying one, with a lens, from the big auction site. Shutters alone seems to be very scarce. A fair one with a 240 Nikkor W or similar would cost somewhere around $300 to $400.

Manageable perhaps, but still I don't need another 240. And then I would pay double for that shutter compared with the lens.

Perhaps I'm missing some obvious way to find a shutter in another way?
Or not....

[karl french]

$300 for decent Copal 3, even if it has a Nikon W 240 in it, is a fair price. Depending on the age of your 355 G Claron it may fit into a Copal 3S.

[Dugan]

Post a WTB ad in the WTB subforum.

[lassethomas]

$300 for decent Copal 3, even if it has a Nikon W 240 in it, is a fair price. Depending on the age of your 355 G Claron it may fit into a Copal 3S.

It's a late 70-ish, serial number 13385277.
Seems to be a #3 with M58 and a mounting of 62mm

[lassethomas]

Post a WTB ad in the WTB subforum.

Good, thanks. Never thought of this forum as a buy/sell forum

[Oslolens]

Here is one for $248. Only the front cell to sell or give away https://vi.raptor.ebaydesc.com/ws/eBayISAPI.dll?ViewItemDescV4&item=284203593662&category=3323&pm=1&ds=0&t=1618048131147&cspheader=1

Sent fra min SM-G975F via Tapatalk

[Greg]

A few years ago I sat down and called some medium to smaller camera stores in NYC. Most are pretty much 100% digital so expect to have to describe to them just what a leaf shutter is. Ended up in acquiring a NOS Copal 3 and a NOS #5 Ilex in their original boxes for under $250 each. Pre Covid 19 I was corresponding with an another photographer in NYC and he told me that there were still a bunch of NOS shutters lying around in backroom storage areas that he knew of. Unfortunately he wouldn't pass on to me which stores he was talking about. About 2 years ago also acquired a like new 300mm Imagon in a Copal No. 3 minus the diffusion discs for under $200.00, "Buy it Now" on eBay. Plan on selling the lens part and repurposing the Copal shutter in the future. Just keep your eyes open and out there... and good luck.

[neil poulsen]

My 355mm G-Claron was originally barrel mounted. Purchased from Kerry Thalmann, he mounted the front and rear elements into a Copal 3 intended for a 210mm lens. I believe this means that, to obtain a given f-stop, I set the aperture to that f-stop on my 355mm G-Claron lens, and then open the aperture by a correction of 1.5 stops. (Actually, 1.52 stops.)

The calculation for this correction in stops isn't obvious and involves logarithms. The point is, one doesn't necessarily need to have a new aperture scale made, if the shutter you purchased was intended for a different focal length lens.

My calculation is the following . . .

Correction in Stops = log[355*355/(210*210]/log(2) = 1.52

This works for logarithms of any base. So, it works for log10(x), ln(x), etc.

[lassethomas]

My 355mm G-Claron was originally barrel mounted. Purchased from Kerry Thalmann, he mounted the front and rear elements into a Copal 3 intended for a 210mm lens. I believe this means that, to obtain a given f-stop, I set the aperture to that f-stop on my 355mm G-Claron lens, and then open the aperture by a correction of 1.5 stops. (Actually, 1.52 stops.)

The calculation for this correction in stops isn't obvious and involves logarithms. The point is, one doesn't necessarily need to have a new aperture scale made, if the shutter you purchased was intended for a different focal length lens.

My calculation is the following . . .

Correction in Stops = log[355*355/(210*210]/log(2) = 1.52

This works for logarithms of any base. So, it works for log10(x), ln(x), etc.

Thanks for the algoritm. I also got a shutter originally for a 210 mm lens.
One thing though, is that the algoritm doesn't account for is differences in magnification of the front cells (since apertures are measure at the front pupil).
When actually measuring the aperture in my specific combination I found that I needed to compensate an additional 1/6 of a stop.

Not a big deal for black and white but perhaps something to be aware of if you shoot a lot of slides.