Re: [APML]: Classic guiding debate (was Mirror Flop)

[cvedeler@bio2.edu (Chris Vedeler)]

Wil, you make an excellent argument to use off axis guideing instead of
using a guide scope.   I have the Lumicon GEG, but must admit that I have
not spent much time trying to get it to work as a guider.  I bought it
originally to work with my medium format camera, but kept it because of it's
ease of use and un vignetted view with my OM1.  I've been pretty happy with
the guiding of my guidescope for the most part (under an hour exposures with
the mirror locked down), and so didn't consider going back to the GEG to see
if I could get it to work with my 208XT autoguider.  Several months of
frustration left a bad taste in my mouth about OAG.  I've taken a lot more
and much better astrophoto's using my guide scope than I did using the OAG.
However, to break the hour barrier I've got to make a choice. Whether to
engineer a better way to lock the mirror down and eliminate the remaining
flexure issues or invest the time to get my GEG to work as a guider.

I feel a little like a pioneer here.  Getting a guide scope to work with a
SCT for long exposures is a challenge, and few people seem to have been
interested in taking it.  Great astrophotos is the goal for most of us, but
the process is half the fun I think.  

Chris Vedeler
http://www.isomedia.com/homes/cvedeler/space.htm
Tucson, AZ



At 11:49 AM 1/28/98 -0700, you wrote:
><snip>
>
>The foregoing is not meant to discourage those who want to experiment with
external
>guide scopes on SCTs, because some have done some valiant and valuable work
in that
>regard and I hope they keep working on it. I'm only arguing that one should
not flee
>from the SCT design purely because SCTs are best guided with off-axis
guiders. SCTs are
>easily the most flexible all-around photo scopes available, and one should
not shy away
>from them on the basis of perceptions about off-axis guiders. (And no, I'm
no "SCT
>bigot": I presently own and photograph with two SCTs, two Newtonians, and
one apo
>refractor.)
>
>
>Wil Milan
>--
>"When I consider your heavens, the work of your fingers, the moon and the
stars which
>You have set in place, what is Man that you are
>mindful of him, or the son of Man that you care for him?"  -- Psalm 8
>
>