[AZ-Observing] Re: Image Question
- From: DBogan3220@xxxxxxx
- To: az-observing@xxxxxxxxxxxxx
- Date: Fri, 5 Sep 2003 09:33:09 EDT
In a message dated 9/4/2003 11:38:38 PM US Mountain Standard Time,
spicastar@xxxxxxxxxxxxxxx writes:
I have an example of a 'recent' uncoated 14.5" mirror around here somewhere,
that has tested out to 1/15th wave, and ready to some day knock somebody's
socks off (first $750 takes heheh). It was made by Pierre Schwaar and I bet
he used the same "technology" as Tom Cave used back in the 50s and these new
guys today.
My opinion of Cave optics is just that, and searching on Cave Astrola gives
you a picture of the decline in quality over the years. I only looked thru
one once a long time ago, and the rest is based only on reputation.
...Old Tom Cave,
Turnin in his grave...
Jack Jones
How do you know that the mirror Pierre ground and polished checked out
to 1/15th wave? Was that P-V or RMS. I know how Pierre ground and figured his
mirrors I was there when he did my 14 inch mirror. BTW I know how to use a
knife edge too. I have a 12 inch mirror sitting in my cabinet that I did under
Pierre's supervision that just needs final polish and then testing.
As far as Cave mirrors are concerned, They were hit or miss, the quality
of the mirror was dependent on how may back orders they had. If they had to
ship whether the mirror was ready or not it went off to the coaters the idea
being that the new telescope owner would not know the difference!
The mirrors that are coming from Swayze. Zambutto Tom Hall and many
others are really much better than anything you could get from years past.
There
are testing methods available today that are much better than what was
available 30 years ago.
Clear Skies
Dwight L Bogan
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