On 9/26/11, Brent Watson <brentjwatson@yahoo.com> wrote:
The other disadvantage of the inverted mount is that an additional mirror may be needed when the sun is high. So many trade offs, and everyone makes them differently. That's why the world is interesting.
You've called attention to a drawback of the Gerrish, namely, the entire sky just isn't accessible in any version of the mount, without additional mirrors. Fortunately the ecliptic is, as is most of the DS "Good Stuff". Really, I like Bruce's ADA mount at SPOC. Full equatorial, and to accomodate different users, the entire intstrument is raised or lowered. It's essentially a motorcycle lift with a telescope instead of motorcycle. My ultimate plan for my own Gerrish is a heated backyard observatory, for winter use. But with Erik and Deloy's help, it can serve chair-bound observers for a season or three, before I scrape the funds for the observatory together.