rudy@xxxxxxxxxxxxxxxxxxx (Ruediger Betzold) moved upon the face of the 'Net and
spake thusly:
> Just wondering what is a T2 ring / adapter ?
> seller claims it is for astrophoto and other usage, but in
> 'The Unofficial Olympus Sales Information File'
> side there is no such thing ?
T2 is an enhancement of the "T-mount" system which was an attempt at a
universal screw-mount system.
T-mount has the same diameter (42mm) as the M42 (aka Pentax Screw)
mount, but a different thread pitch (T mount is 42x0.75mm, M42 is
42x1mm). T-mount lenses also sit much further from the film than any
other kind of lens (including M42), allowing plenty of room for a fat
adaptor.
T2 is a modification of T-mount which allowed some limited aperture
coupling.
You could indeed use a T2 ring (an ring about 10mm deep with a male OM
coupling on one end and a female screw thread on the other) to connect
to a "T adapter" mounted on a telescope. An ordinary T-ring would be
cheaper and easier to find.
More info here:
http://www.smu.edu/~rmonagha/bronmounts.html
Sometimes you will find an old lens in a pawnshop which has a mount
for some weirdo BogoFlex camera, but sometimes the mount unscrews
leaving a T-mount thread. These lenses are often on sale for $10
because nobody knows what to do with them. If you have a T-mount
ring, you'll know what to do with it!
--cjb
p.s. I'm getting a vast sense of deja vu here. Did somebody ask this
same question recently?
--
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--- Christopher Biggs - Stallion Technologies - chris@xxxxxxxxxxxxxx ---
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