On May 23, 2022, at 11:21 AM, Roland Christen via groups.io <chris1011@...> wrote:



Mak-Newts have only 3 optical surfaces aside from the diagonal flat. Those 3 surfaces are spherical, so can be produced with extremely high accuracy and smoothness. The field curvature is essentially flat for even the widest field eyepiece. Coma is a tiny fraction of what a parabolic Newtonian mirror produces and cannot be seen in any wide field or high power eyepiece. There is no spider diffraction to spoil a high power view of a bright planet. The front corrector glass is hard borosilica crown which is the least expensive glass available and is available in the highest internal quality. The tube is closed, so no dirt will fall on the mirror surface. Alignment (collimation) of the mirror is not an issue since it is spherical, so it can be permanently aligned at the factory.

Rolando

-----Original Message-----
From: Jeff B <mnebula946@...>
To: main@ap-gto.groups.io
Sent: Mon, May 23, 2022 8:41 am
Subject: Re: [ap-gto] 110 scope musings

"P.S. I still love Mak-Newts and I think they are about as perfect an optical system that exists for visual only.*

And a nice size Mak-Cass for imaging only. But ne'er the twin shall meet to produce both results at the same time."

*ask me why"

I'm still asking Roland.  I love MNs too for visual and always have one around, most recently my MW/APM MN86.

I would love to see you make a run of say, 8", 10" and maybe even a 12" MNs say, perhaps F5.6.

Jeff

On Sun, May 22, 2022 at 11:32 PM Don Anderson via groups.io <jockey_ca=yahoo.ca@groups.io> wrote:

Very impressive Roland! I love my refractors for the very reasons you described. They fill a  in the visual/photographic world of this hobby. I am looking forward to using my brand new 92 Stowaway that I recently received. It fits perfectly on my AP900GOTO
Along with my other two gems! Will follow the development of the 110 Starfire with great interest.
Don
Astro Equipment | Flickr

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Roland Christen
Astro-Physics