Re: 9.25 lives up to its Rep


"Michael McCulloch" <michaelm@xxxxxxxxxxxxxxxxxx> wrote in message
news:17kdi1dfgnemm97vqibhssv3r4988c1ud5@xxxxxxxxxx
> On Tue, 13 Sep 2005 06:27:52 -0400, "Stephen Paul"
> <smarshallpaul@xxxxxxxxx> wrote:
>

> I also own a C9.25 on a Sphinx mount and I agree that is an excellent
> scope for planetary observing. What I do miss are the views thru a
> 12.5" (or larger) newt of globs, or objects like the Veil in a
> wide-field EP like a 35mm Pan.

I understand completely, but....

>
> The C9.25 just doesn't do justice for those objects (aperture still
> rules) and it is difficult to get enough reduction in magnification to
> make deep sky binoviewing very satisifying.

Operating from my backyard with magnitude 5+ skies, it's a trade off I'm
willing to accept.

I look at it this way, before, I had the 12.5" Dob and the 80mm ED refractor
for visual use. The 102EDF9 was a nice scope but demanded at least a CG-5,
which is sort of a here nor there mount. Fine for visual use and limited
imaging, and a decent GoTo mount for scopes as large as the C9.25, but not
really a solid enough mount to qualify as "simply a pleasure to use no
matter what the application". Primarily this is a result of the sorely
missing "slip" clutches. The Dob is often more work than I want to get
involved with. It's large, bulky, and personally I can't stand the sitting
positions and contortions that go along with using one, especially at higher
altitudes. The views are awesome, but the comfort is just not there for me.
The 80mm refractor is very aperture limited for anything other than
binocular-like views, although it definitely has the advantage of up to 80x
on deep sky, and up to 60x per inch on the moon and planets, which is
primarily why I kept it over the 102ED F9. It fills that niche nicely,
without a large mount requirement.

For me the C9.25 on G-11 may just be the ultimate trade-off in aperture/ease
of use and comfort. It performs much like a 10" Dobsonian in terms of light
grasp and resolution, but with all the benefits (and expense!!) of a rock
solid GEM with an easily removeable OTA that has the eyepiece in any seated
position you'd like it, with just the turn of a screw.

Since I primarily wanted the GEM for imaging originally, this is an ideal
"single mount" solution. (But even if I hadn't, I still like this
arrangement better than anything else I've tried, and that includes
monopods, tripods, GoTo forks, forks on wedges, dobs, altazimuth heads, and
CG-5 class GoTo mounts.)

> Have you tried the Denk
> StarSweeper and if so how well does it work with the C9.25?

Don't think I will either. Truthfully I only use the binoviewer for planets
and brighter DSO's that beg for the two eyed wow factor, and yet fit in a
half degree field. If I decide to do "deep" deep sky with the binoviewer,
I'll move up to the C11, and then go for the StarSweeper arrangement. As
much as I'd like to do that for the aperture, I just think it's unwise
because it will incur a greater cool down time.

FWIW, in my opinion, the C9.25 with binoviewer is about as bright as the C8
without, but with improved resolution. What I "am" considering is getting
the 6.3R/C and then using the 24mm Pan as my largest field eyepiece to
eliminate the field curvature evident in the 35mm Panoptic. This actually
provides a larger true field of view than the 35mm at F10, and flattens out
the field. It also provides 1 arsecond per pixel resolution for the DSLR,
which may preclude my need for the 200mm F4 Newt OTA and a tele-extender,
given that I also have the 600mm focal length Orion 80ED. (I can get 600mm
and 1500mm without the Newt.) If I then setup the C9.25 for piggy backing
the 80ED, I'm down to one imaging setup that does it all, as well as working
very nicely for visual. (Although I would also still use the 80ED on the
UniStar Light when desired.)

Ultimately this move would represent an overall downsizing of equipment for
me. I could then sell the 35mm Pano and the 2" Visual Paracorr (both of
which I bought fo my Dob), and get back more than I paid for the C9.25
(used). Add the price of the Dob and the 200F4 Newt into that mix and I
also got the G-11 for a third of the going rate on Astromart. :-)

All total, I'm out $500 in the trade. Not bad considering the added utility,
and the readiness factor of this setup Oftentimes my viewing sessions are a
half hour to an hour in length. I'm perfectly content to take the scope out
and poke at all the brighter Messiers that are easy to spot in the 9x50
finder, giving each about 5 minutes before putting everything away. Since
there virtually is no setup time with this configuration, that's now very
possible and productive, even when the seeing isn't great, or the scope is
not completely cooled down to planet observing status.

Believe me, it's proving to be the case that grabbing the handle on the
ScopeBuggy, wheeling this thing out of the garage, onto any spot in the yard
I chose, aiming the polar scope roughly at Polaris and then swapping the
corrector cover for the dew shield is virtually zero effort. And if I don't
like that position, I just grab the handle and wheel it somewhere else. It
only takes a minute to re-aim the mount at Polaris. It takes longer than
that, and with more effort to move the Dob to a new location.

Further bolstering the utility of this arrangement, contrary to what some
have stated, the only reason to level a GEM is to make drift alignment
easier. The polar axis is given it's name for a reason. If it's aimed
roughly at the pole, then you only need the clock drive and an occasional
button press to compensate for less than perfect polar alignment. If someone
had the patience to drift align a GEM without a leveled tripod, well God
bless them, it can be done. :-)

>
> The "Holy Grail" of setups? I wouldn't be so quick to make that
> judgement. ;-)

Well, I did say "my" Holy Grail. As they say, "to each his own." ;-)

Thanks for the discussion,
Stephen


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