Re: ATM very fast dob (f/D<4)

[Aplanatic@aol.com]

Dave Pitou wrote:

> I am considering a f/3.5 for my next scope, but I suspect that's the limit.

I am peripherally involved (as a glass pusher, sweat generator) in an 
upcoming project to make a 42" f/3.3 Dob-Newt.  A four-element coma corrector 
has been designed for this optical system and shows excellent visual 
performance when used with Nagler eyepieces.  The prototype Nagler eyepiece 
optical design was taken from the original patent and used in a ray trace to 
design the corrector. 

If there is interest, I am willing to act as scribe for this project, keeping 
folks on the list informed.  Figuring this huge, fast mirror should be 
amusing....

The cellular blank is being annealed right now in AZ and should arrive in LA 
in couple of weeks (barring some disaster).

Dave Rowe
Torrance, CA