Re: [ATM] Aplantic folded Gregorian variety

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

At 17:37 8/14/05, vladimir wrote:
>Played with my favorite 2-mirror design, and come up
>with folded 3-mirror+diagonal design that uses two
>spherical (including primary) and one moderately ellipsoidal
>mirror. The specs for an effective 300mm f/4.15 system are:
>

I proposed some folded Gregory designs with similar geometries about 
6 years ago -- here's the ATM list archive link: 
<http://astro.umsystem.edu/atm/ARCHIVES/AUG99/msg00093.html>. As 
specified the design is an all reflective Schmidt: it eliminates 3rd 
order SA, coma, and astigmatism leaving only Petzval field curvature. 
The original idea was due to Baker (see e.g. figure 3.75 in Wilson vol. I).

Needless to say there's been no rush to build one of these.

Mike Peck


_________________

Michael Peck
email mpeck1@ix.netcom.com
Wildlife photoblog! http://wildlife-pix.com
Amateur telescope making http://home.earthlink.net/~mlpeck54/astro/astro.html 

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