25 Sep
2010
25 Sep
'10
12:11 p.m.
[Leica copies and their lens threads]
Certainly 42mm and a finer pitch... 0.75mm sounds about right.
Yes. I've enver actually come across that one, my video cameras have the
C mount register. There's also D mount, used on 8 mm cine cameras. Also
32tpi, but a smaller diameter. And I suspect a shorter register.
I'm pretty sure that the FED was 1mm pitch,
don't know about the Zorki, or
particularly the early East German counterfeit Leicas.
My guess is that the FED and Zorki are the same, I've never had any
problems fitting lens from one to the other, but I don't own the original
models. The later ones are not really Leica copies -- they're rangefinder
cameras with the same lens mount and register, but the shutter mechanism
is very different (for example Leica never made a screw-mount camera
with slow speeds on the same dial as the dfast speeds, Zorki did (and
IMHO the way it's done is ingenious).
Pentax/Praktica/Edixa thread is certianly 42mm *
1mm pitch.
But, IIRC, "T-mount" is 42mm x .75mm pitch And C mount is 32 tpi.
"CS
mount" is the same, but with 5mm difference in registry (distance to
film plane) Some computer parts have metric fasteners, some
don't.
Yes. It's not at all uncommon to find a mixture of threads in the same
machine, particualrly when sub-assemblies (PSUs, disk drives, etc) are
bought-in.
European machines are almost always metric. Old US ones (DEC, HP, etc)
are almost always UNC (4-40, 6-32, etc). I have both sets of spanners in
my toolkit, along with a set of BA spanners for when I work on Creed
teleprinters :-)
-tony