[ATM] ATM: simplest ever unobstructed scope

["David Harbour" <stainless_steel@suddenlink.net>]

All:

I haven't read anyone posting about the virtues of the tilted component 
system that is essentially a Newtonian, with a tilted primary mirror, and 
two simple menisci just downstream from the diagonal to correct for the 
induced astig. and coma. I have seen versions of this several times in Sky 
and Tel, over the decades. Surely someone else has.

I corresponded with Sherman Shultz (with a 75 year old typewriter, ink on 
paper, many decades ago) about curing the astig. in his 20, or 24" Newt 
(Yoke mounted, ala Hooker 100") at McAlester College; he favored a tilted 
zero power meniscus, and I favored a little warping harness for the 
diagonal. What ever happened to Sherman Schultz?

What ever happened to Roger Tuthill, who built that neat Maksutov Newtonian, 
with tilted components, as an unobstructed Newtonian; why is he not on our 
list of elite atms? Was he ever? And I have gotten to thinking about the 
other pioneers from my stacks of now long gone S & T mags- was Arthur 
Leonard ever on our list? Where is everybody?

Also, If I was going to try an unobstructed instrument with tilted 
components, I think I would go for one of those designs I saw that were 
reported to have functioned acceptably- the two or three designs I saw as 
Newts with a little meniscus, or two, tilted, each, just before the diagonal 
(out of harm's way of entering light). Does anyone else think that this idea 
bears investigating?

A long time ago, I asked the great Thomas Cave if I should buy a largish 
Cassegrain (I talked to him on the phone, when he was still advertising) he 
said I could make a Newt into a kind of Cass. just by buying a good Barlow 
lens, and for far less dough. I did just that; many, many years (decades) 
ago. I understand he has passed....

R-101

P.S. How did the Herschels ever cure the astig. and coma, that they must 
have had in horrendous amounts, in their big scopes? Does anyone know? There 
are some interesting "legends" about the Herschels- 


_______________________________________________
ATM mailing list http://www.atmlist.net/