"ATIPPETT" wrote in message
...
I am confused as to the use of the term copal. I have
seen it in references to
lens board openings, in referecnes to shutters (separate
from the lens), and I
have seen it in both upper and lower case.

I found one reference that copal #00 was a 25mm opening.

So what is copal/Copal #0, #1, #3, and #3S and how do they
relate to lens
boards.

Thanks
Alan Tippett

You will find information on all new Copal shutters on
Steve Grimes shop web site at:
http://www.skgrimes.com/products/index.htm

This gives dimensions of the shutters and sizes of
mounting holes.
Copal is a Japanese shutter of high quality, although I
think the old Compurs were better. Nonethelss, Copals are
very widely used for high quality lenses and are about the
only game in town. Copal makes both settible and
self-setting shutters. They call the self-setting variety
"press" shutters but this is a misuse of the term. A press
shutter was a shutter with a blade arrestor allowing ground
glass focusing without changing the speed setting.
Self-setting shutters are convenient and simple, shutters
that need to be cocked can have much stronger spring motors
and give higher shutter speeds.
S.K.Grimes also sells rebuilt old shutters which can
sometimes be an economical choice, or in the case of very
large shutters, the only choice.


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Richard Knoppow
Los Angeles, CA, USA