Re: [ATM] ATM chinese puzzler

[Michael Peck <mpeck1@ix.netcom.com>]

At 21:32 07-04-04 -0700, Guy Brandenburg wrote:

>So that's the puzzle: assuming that my American
>businessman's report is reasonably accurate, then what
>was in that 'fan' device? How can a 3 to 5 second test
>of an otherwise untested mirror tell for sure whether
>it's any good or not, and if not, what needs to be

Somehow all the posts in this thread ended up in my trash bin. You must 
have inadvertently been caught in one of my many spam traps.

Anyway, I would make the same guess as earlier posters did. It's probably 
an LED and ronchi grating or knife edge, maybe with a small telescope for 
easier viewing. I think all the mirrors in the 3-6" range being shipped out 
of China are reported to be spherical, so a quick look should be good enough.

And now, some old-timer's reminiscence. My very first telescope, which my 
parents bought for Christmas in - probably - 1966, was an Edmund 4 1/4" 
f/10 reflector. It had a spherical primary (guaranteed 1/4 wave!), a 
rectangular diagonal that was glued to a stalk, aluminum tube, rack & 
pinion focuser, and something like a 6x30 finder. It was mounted on a GEM 
with maybe 1/2" shafts and cast iron housing and the head sat on a cast 
iron pier. It came with a 1" f.l. Kellner eyepiece, 1/2" Ramsden (no metric 
nonsense then), and 2-3X Barlow. As I recall that model was advertised at 
about $80 in the 1966-67 Edmund catalog.

According to the inflation calculator at <http://www.bls.gov/cpi/home.htm> 
80 1966 dollars had the same buying power as about $460 today. A quick look 
at Orion's web site shows what looks like a dozen or more reflector models 
at that price or lower, including Dobs as large as 8" for under $400. 
That's about the same price as Edmund's top of the line 8" model sold for 
then, which would have been way out of my parent's price range.

Personally I'm not inclined to scoff at those Chinese optics, or begrudge 
those Chinese optical workers their jobs. They, and Meade, Celestron, Orion 
et al. are making stuff available that a 12 year old kid could barely have 
dreamed of owning 40 years ago, at much lower prices relative to average 
North American incomes, with probably the same or better overall quality.

Mike Peck

_________________

Michael Peck
email mpeck1@ix.netcom.com
Wildlife photography page http://home.netcom.com/~mpeck1/index.html
Amateur telescope making http://home.netcom.com/~mpeck1/astro/astro.html

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