Re: [ATM] ATM chinese puzzler

["James Lerch" <jlerch1@tampabay.rr.com>]

I'll bite :)

Ok, we have 6" mirrors, and an inspector 8 feet away, obviously doing a test at
the Radius of Curvature.  Assuming this is correct, it sounds like the
"inspector" is testing 6" F/8 optics.

So the "Chinese Fan" could be one of two things

A) A simple battery powered light source and knife edge, with the inspector
simply looking for a spherical null

B) A simple battery powered Ronchi tester, and the inspector is looking for
straight lines.

While crude, the test method should work.

Now, if the "inspector" was a little closer to the optics, (or the optics larger
in diameter) indicating the need to test faster optics, the "Chinese Fan" could
be same as A & B above, but this time with a built in Ross Null lens, again
giving a simple Go/No-Go answer.

If I had to test a dozen or more optics every day of this size and F-Ratio, I
might just go this route :)

BTW, If I had to wager, I'd bet the Filthy shop produces the best optics of the
bunch :)

Take Care,
James Lerch
http://lerch.no-ip.com/atm (My telescope construction,testing, and coating site)

"Anything that can happen, will happen" -Stephen Pollock from:
"Particle Physics for Non-Physicists: A Tour of the Microcosmos"

" Press on: nothing in the world can take the place of perseverance.
Talent will not; nothing is more common than unsuccessful men with talent.
Genius will not; unrewarded genius is almost a proverb.
Education will not; the world is full of educated derelicts.
Persistence and determination alone are omnipotent. "
                                                           Calvin Coolidge

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