[LargeFormat] Compur #1 and Copal #1 for G-Claron 305mm f9

[Frank Filippone]

Secrets on the Iris plate.......
Let's assume you already have an iris plate, for a 210 lens.  A rather
common lens for a Copal1 shutter.

210mm = marked F stop
240mm = +1/3 stop.. is, as marked,  F11 is 1/3 of the away from F11 towards
F16.
270mm = +2/3 stop
305mm = +1 stop

SO if you have that 210 Shutter, for an F5.6 or 6.3 lens, it is a rather
easy change to just make a mental note to set the shutter 1 stop more open
than the scene requires......F6.3 = Wide open, F9,  on a 305 lens.  Pretty
neat?

Rmemeber that just becuse the iris markings say the lens is at F5.6, this is
not true for the G-Clarons.. the largest aperture POSSIBLE is F9.
Pay no attention to the scales when they go bigger than  F9.

My G-Clarons are all in standard Copal 1 Shutters... I just switch the
elements, keeping the F-stop ring the same.  I use no shims.


Frank Filippone
red735i@earthlink.net http://www.pairlist.net/mailman/listinfo/largeformat