Celestron G9 9.25" Schmidt-Cassegrain?
Carl Wilson
purchase of a Celestron G9 9.25" Schmidt-Cassegrain. Has anyone had any
experience using this particular scope? I'm particularly interested in it's
optical and mechanical quality, and it's suitability for possible CCD
imaging in the future.
Ross Bench
>
> The optics on the 9.25" seem to be generally the best (and most consistent
> of the major SCT choices). Mine was very nice optically, though I also had
> on a G-11 mount. From what I hear the standard mount now is pretty weak for
> this scope, but for the price it is not a bad deal.
Chris;
How much does the 9.25 OTA weigh ???
Chris Adamson
of the major SCT choices). Mine was very nice optically, though I also had
on a G-11 mount. From what I hear the standard mount now is pretty weak for
this scope, but for the price it is not a bad deal.
Chris
Carl Wilson <ca...@sonetcom.com> wrote in message
news:G9D94.15327$Ym1.5...@tw11.nn.bcandid.com...
Carl Wilson
should look into buying just the Celestron 9.25" OTA and place it on a
different mount? I'd hate to buy another scope with a poor mount. That was
the primary fault with my Mead 826C when I first bought it. Beefing it up
added considerable weight, and as a result it became less portable. Any
suggestions on a good mount at a reasonable price?
"Chris Adamson" <adamso...@home.com> wrote in message
news:VhD94.14577$Fw1....@news1.rdc1.az.home.com...
John Hagan
Your best bet would be the 9.25" OTA on a Losmandy G11 mount, but
that's going to be $3000+. If you want to save a little and still have
a mount that will handle the scope well, the GM-8 mount will work.
I've seen the old G9 with the GM-8 head on a *very* weak tripod. The
mount was fine but the aluminum legs could barely support the set-up.
The good news is that I just spoke with Mike at Astronomics and they
have a few of these left over. It is possible to replace the
lightweight Celestron tripod with Meade's adjustable field tripod,
which should give you plenty of stability for visual use and probably
enough for photography, providing you keep the weight of your
equipment reasonable. Short of getting the heavier G11, this is
probably your best bet.
(BTW, I have worked with the Ultima 9.25" and the optics were very
good.)
John Hagan
On Mon, 27 Dec 1999 00:39:03 -0600, "Carl Wilson" <ca...@sonetcom.com>
wrote:
Alan Figgatt
should be aware that the 9.25" SCT is a noticeable step up in size from the 8",
if you haven't seen one. The 9.25" SCT has a longer focal length primary mirror
than the standard SCT design and has extra space at the back of the OTA for the
now deleted focuser counter, so the OTA is approx 5.5" longer than the C-8 OTA.
I mount my 9.25" SCT on the Losmandy G-11 mount which makes for a very stable
platform, but this is not what I would call a very portable setup. It takes me
20+ mins to setup at my club's dark sky sites at a minimum. The GM-8 should be
able to handle the 9.25" SCT for visual use, but for serious imaging work, I
would go with the G-11 or equivalent grade mount. Optically it is quite good,
though as with any SCT, keeping it well collimated is critical.
Clear skies,
Alan Figgatt
Northern Virginia Astronomy Club (NOVAC)
Ross Bench wrote:
>
> Chris Adamson wrote:
> >
> > The optics on the 9.25" seem to be generally the best (and most consistent
> > of the major SCT choices). Mine was very nice optically, though I also had
> > on a G-11 mount. From what I hear the standard mount now is pretty weak for
> > this scope, but for the price it is not a bad deal.
>
Alson Wong
considering buying the C-9.25 on the Celestron mount from Pocono Mountain
Optics, and upgrading the mount later. The OTA sells for $1195, while the
OTA plus Celestron mount is only $1299. I've not seen the Celestron mount,
but it may be good enough for low and medium power visual work and piggyback
astrophotography. The mount may be less than ideal, but at an additional
cost of only $104, it's not a bad deal to start with; the mount can always
be upgraded to a GM-8 or G-11 later.
--
Alson Wong
Riverside Astronomical Society
http://www.pe.net/~wpl/ras.html
Visit my Web page at <http://home.earthlink.net/~alsonwong/index.htm>
Alan Figgatt <afig...@erols.com> wrote in message
news:38679260...@erols.com...
Dan Cook
>I have the same setup as you and agree completely. A member of my club is
>considering buying the C-9.25 on the Celestron mount from Pocono Mountain
>Optics, and upgrading the mount later. The OTA sells for $1195, while the
>OTA plus Celestron mount is only $1299. I've not seen the Celestron mount,
>but it may be good enough for low and medium power visual work and piggyback
>astrophotography. The mount may be less than ideal, but at an additional
>cost of only $104, it's not a bad deal to start with; the mount can always
>be upgraded to a GM-8 or G-11 later.
I'd recommend purchasing the OTA and mount separately. Purchase the
Losmandy G-11 mount instead of the Celestron mount. They are not the
same. Anything less than a G-11 will just be a (needless) excercise in
frustration. The best way to learn is from _others_ frustration, not
your own. :-)
- Dan
Frank Varisco
not the most "portable" but is not too bad, either. It's a bit of hassle if
you want to go out into the front yard for a 30-minute session. It takes me
about 10-15 minutes to set up the OTA and tripod and another 20 to hook all
the gadgets (heaters, polar align, etc.) It will be even less portable on
the G-11 (the minimum mount if you're planning to do astrophotography.)
This specific model has an excellent reputation for its optics, though See
Todd Gross's site for pictures that he took with it.
Frank Varisco
Tom Davis
I own the CG9.25 variety of this scope (Losmandy
GM8 mount). Optics are quite good. It definitely
has a noticeble difference in brightness between it
and the 8". Mechanical quality on the tube is better
than the other Celestron models, with no plastic used
at all. I have minimal image shift. The finder is too
small being a 6x30. I upgraded mine to 9X50 unit.
The mount is not really up to the job of CCD imaging,
if that is planned later. The older GM8 version (with
a more solid tripod. I use a G11 tripod), is useable,
with a G11 the best choice.
To buy the 9.25" optical tube alone would cost only
about $150 less than the entire scope. So it might
not be a bad idea to buy the entire scope, use it
for a while, and sell the CG5 mount as a down-
payment on a bigger mount when you are ready to get into CCD work later on.
Thanks, Tom Davis
Carl Wilson wrote in message ...
John Burgan
problems. Also, the accessories (star diagonal, etc) are sub
standard. The C8 deluxe drive will not work with some auto guiders because
it won't accept corrections in both axis at the same time. I'd
stick with Meade if I were you.
David Silva
> The mount for the G9 does look to be a bit on the weak side. Perhaps I
> should look into buying just the Celestron 9.25" OTA and place it on a
> different mount?
I have a C9.25 on a GM8 mount. The normally provided lightweight tripod is
acceptable for visual use with this scope, using the HD Tripod ( comes with
the G11 ) firms things up very nicely. Mine is mounted on a side by side
saddle with an 80mm finder.
I haven't done imaging with this setup, but visually it is fine.
-David
Carl Wilson
what I can get into for what price. I've done business with them before,
and always liked the service. Besides, it's a fairly short ( 90 minutes or
so) drive to their shop in Norman.
Thanks again!
Carl
"John Hagan" <phiz...@nospamrcn.com> wrote in message
news:38670cdb....@news.rcn.com...
> Hi Carl
>
> Your best bet would be the 9.25" OTA on a Losmandy G11 mount, but
> that's going to be $3000+. If you want to save a little and still have
> a mount that will handle the scope well, the GM-8 mount will work.
> I've seen the old G9 with the GM-8 head on a *very* weak tripod. The
> mount was fine but the aluminum legs could barely support the set-up.
>
> The good news is that I just spoke with Mike at Astronomics and they
> have a few of these left over. It is possible to replace the
> lightweight Celestron tripod with Meade's adjustable field tripod,
> which should give you plenty of stability for visual use and probably
> enough for photography, providing you keep the weight of your
> equipment reasonable. Short of getting the heavier G11, this is
> probably your best bet.
> (BTW, I have worked with the Ultima 9.25" and the optics were very
> good.)
>
> John Hagan
>
> On Mon, 27 Dec 1999 00:39:03 -0600, "Carl Wilson" <ca...@sonetcom.com>
> wrote:
>
> >The mount for the G9 does look to be a bit on the weak side. Perhaps I
> >should look into buying just the Celestron 9.25" OTA and place it on a
Carl Wilson
spent a good chunk of cash on a new scope, and then turn around and tell her
I need to spend another large chunk of cash to replace the original mount
because it is inadequate. No sir... I spent twenty years in the military
and have almost been killed on a couple of occasions, but I'm just not
*that* brave! Better to hit her up once for a good setup to begin with! ;-)
"Tom Davis" <tda...@salisbury.net> wrote in message
news:848skh$147k$1...@news.inc.net...
Tom Davis
I understand. It would actually make the scope cost less, though. If
you bought the scope for $1299, then sold the mount for $300
on AstroMart, the optical tube would cost less than a separate
purchase of the optical tube alone.
Apart from that, the optical tube on a GM8 or G11 would be the
next best way to go. A GP-DX would probably work OK, but by the
time you add the expense of the dual-axis drives, the cost is about
the same as the GM8.
Thanks, Tom Davis
Carl Wilson wrote in message ...
Brian
tripod and it is heavy and rock steady.
--
Brian
--------------------------------------------------------------------------
Please remove 'nospam' from email address before replying.
reply to: bdpli...@mindspring.com
David Silva wrote in message ...
>"Carl Wilson" <ca...@sonetcom.com> wrote in message
>news:RQD94.15382$Ym1.5...@tw11.nn.bcandid.com...
>> The mount for the G9 does look to be a bit on the weak side. Perhaps I
>> should look into buying just the Celestron 9.25" OTA and place it on a
>> different mount?
>
Tom Davis
same as the GM8 according to Scott Losmandy - except for the
tripod), with a G11 tripod replacing the inadequate Celestron
aluminum unit. It brought the damping time down to about 1 second.
In fact this same mount works just fine with my 6" F/8 refractor.
The only issue for anyone considering buying one of the CG9.25s that
dealers have left over, relates to bearings. Some of the early units
had nylon bushings instead of roller bearings. I had to replace mine
on both the RA and Dec axis. It costs about $40.00 for the bearings
from Losmandy if you can do the work yourself. It took me about two
hours for the whole procedure. If they have the bearings already, it
may be possible to get the whole scope and upgrade to the G11
tripod for about the same as the C9.25 OTA and GM8 combo with the
standard GM8 tripod.
Thanks, Tom Davis
Brian wrote in message <84ag9c$84a$1...@nntp9.atl.mindspring.net>...
Carl Wilson
of my CCD imaging from my backyard (reasonably dark with some screening),
would the supplied head that comes with the G9 mounting be adequate for CCD
imaging if mounted on a pier?
"Tom Davis" <tda...@salisbury.net> wrote in message
news:84afaa$17j$1...@news.inc.net...
Tom Davis
If you are referring to the CG5 that comes with the
G9, it would probably not have an accurate enough
drive. I have the one that came with my CR150 6"
refractor upgraded with wooden legs from a GP
mount. It is vastly more stable, but not near so much
as the GM8 (or Losmandy G9 - that is where I am
confused - which one do you mean?). The scale
of the CG5 head is not large enough for the 9.25"
optical tube. The motor drive currently sold is fine
for visual use, but not refined enough for CCD use.
The Losmandy G9 or GM8 with the Celestron tripod,
if remounted on a pier, should be more than stable
enough. Drive accuracy should be OK for 1 to 2
minute exposures unguided. Beyond that, an
autoguider would be helpful. They do have an
autoguider jack on the control panel. If you can get
one that a dealer has sitting around after they have
been discontinued by Celestron, this may be the
most cost effective solution. If you can make a low
cost pier for it, it might be the way to go.
Hope this helps,
Tom Davis
Carl Wilson wrote in message ...
Carl Wilson
anyone had any first hand experience with the LX50 model with either the
8" or 10" OTA?
Gregg Carter
How do you like the 9.25" SCT? Are the star images pretty tight? Out to
the edge of the field?
Thanks,
Gregg
Brian wrote in message <84ag9c$84a$1...@nntp9.atl.mindspring.net>...
>I have the same set-up (9.25 on a GM8 mount). I opted to buy Losmandy's
>tripod and it is heavy and rock steady.
>
>--
>Brian
Brian
I am quite pleased with the CG 9 1/4. In my reading and research on the
subject prior to purchase, I got the distinct impression that the 9 1/4 OTA
was atypical in that Celestron spent more time constructing and finishing
the mirror assemblies and other aspects of the scope. Apparently, they don't
sell as many of this size as they do 8 inch, etc. and this forced them to
retain more human involvement in the process as it was not cost effective to
automate the assembly. In any event, I am quite pleased. I am impressed with
the optics. M13 looks like a filed of diamonds, I get good separation if the
Trapezium, etc. Todd gross also has some nice things to say about the OTA on
his website. You should check out some of his astro photos taken with the
scope.
I personally elected to get the german equatorial mount as opposed to
the fork because I wanted to break the scope down into smaller manageable
pieces. The fork mounted 9 1/4 is huge and I was afraid I would not be able
to handle it safely alone. Also I have been impressed with the notion that
german equatorial mounts are more accurate for photography which I may delve
into someday.
When I bought mine, it was still coupled with the Losmandy head. I think
I got one of the last ones prior to Celestron changing over to the new
mounts. The Losmandy head seems sturdy enough to handle the scope, although
I have heard from others that they feel the need to get the larger G11. For
viewing the GM8 head seems just fine. If you buy the Losmandy head, you
might want to do a search for past threads dealing with re-lubricating the
internal bearings. It makes the RA and DEC movements a bit smoother. I have
done it and it is fairly simple - just takes a bit of time. If you cannot
find past threads with their instructions, Losmandy has them on his website.
hope this helps,
--
Brian
--------------------------------------------------------------------------
Please remove 'nospam' from email address before replying.
reply to: bdpli...@mindspring.com
Gregg Carter wrote in message
<1xca4.1127$5S5....@wormhole.dimensional.com>...
Tom Davis
I owned a 10" LX50. The optics were quite good on the one I owned.
The mount left something to be desired, though. The LX50 does not
have PEC (Periodic Error Correction), and the drive suffered from
a fast period error that made it impossible to use for CCD work.
Also, the standard wedge was insufficient for any serious work. It
was more stable with the super wedge, but quite heavy. I would
recommend the LX200 series over the LX50 to anyone desiring to
use the instrument for CCD use. I have found the CG9.25 to be
a more satisfying instrument for my needs. The optics are of a
consistent good quality (I have yet to hear of a bad 9.25. I have
heard of more than one substandard LX50 8" and 10"), and the
Losmandy GM8 is a definite step up from the LX50 fork mount in
both stability and drive accuracy.
Regarding the comments concerning the C8 problems, I sympathize
with his problems, but I owned both the Celestar 8 and Celestar 8
Deluxe versions, and they both worked just fine. You can get a
bad unit in almost any scope model. I had a real problem with the
LX50 electronics , but I understand Meade has addressed most
of the problems I had experienced with mine. The reason for my
recommendation is the lack of PEC and the better stability of the
German Equatorial mount on the CG9.25.
Thanks, Tom Davis
Carl Wilson wrote in message <38694ABB...@sonetcom.com>...
Herb and Paula York
We started stocking this scope to go on the GM8 and G-11. The new OTAs are
made to fit the G5 Celestron mount so they have the 2+" dovetail. Does
anyone know how you interface these new OTAs to the GM8 or G-11 dovetail?
Scott is on one of his 2-3 week sabbaticals so I can't ask him. I'm fairly
certain he said he isn't making the 9.25" dovetails anymore and suggested we
cut off a C-11 plate.
There has to be a better "no I don't have a machine shop" answer.
Thank you
Herb
http://www.buytelescopes.com online astronomy and camera shop
Anacortes Telescope and Wild Bird
(360)588-9000
Alan Figgatt
to special order the dovetail from Scott; according to Scott, what he did was to
chop off a C-14 dovetail and drill new mounting holes (the C-11 dovetail is 1/2"
too short for the 9.25"). One drawback in my dovetail is that he didn't drill a
hole for the safety screw on the chopped off end.
Clear skies,
Alan Figgatt
Northern Virginia Astronomy Club
Alson Wong
on a G-11 mount. The LX50 had good optics, but the OTA with the heavy fork
arms and wedge attached was at my limit as far as weight was concerned. I
also found that the mount was a royal pain to polar align and counterbalance
for astrophotography. The G-11 is far easier to set up and polar align for
astrophotography.
--
Alson Wong
Riverside Astronomical Society
http://www.pe.net/~wpl/ras.html
Visit my Web page at <http://home.earthlink.net/~alsonwong/index.htm>
Tom Davis <tda...@salisbury.net> wrote in message
news:84bv74$1vnv$1...@news.inc.net...
K3AC
>We started stocking this scope to go on the GM8 and G-11. The new OTAs are
>made to fit the G5 Celestron mount so they have the 2+" dovetail. Does
>anyone know how you interface these new OTAs to the GM8 or G-11 dovetail?
>Scott is on one of his 2-3 week sabbaticals so I can't ask him. I'm fairly
>certain he said he isn't making the 9.25" dovetails anymore and suggested we
>cut off a C-11 plate.
>There has to be a better "no I don't have a machine shop" answer.
>Thank you
>Herb
>http://www.buytelescopes.com online astronomy and camera shop
>Anacortes Telescope and Wild Bird
What do you mean by "2+" dovetail? Is this the same dovetail plate used in the
Vixen GP mounts? Are you stocking the C-9.25" with the new CG-5 Celestron
mount/alum tripod?
Thanks,
Bob
Tom Davis
I was afraid this might happen. Celestron had been making the 9.25
with the Losmandy G11 dovetail. Now, I assume from you post,
they are only making them with the CG5 or GP type dovetail.
I would assume that the only proper answer to this would have to
come from Scott Losmandy. Now that the 9.25 OTA does not
come with a Losmandy dovetail plate, I would assume there to be
enough of a market and reason for him to start producing them again.
Without the proper equipment, cutting down a CG11 dovetail to size
would be less than professional. So the only proper way to do this
is through Losmandy directly.
I would assume that there will be quite a few purchasers of the G9.25
that will find the CG5 mount quite inadequate for there needs, and
as a result, want to upgrade to the Losmandy mount. This would
create a need for dovetail plates that it would make no sense for
Scott Losmandy to ignore, especially since it would mean the sale
of either a GM8 or G11 for each one.
Thanks, Tom Davis
Herb and Paula York wrote in message ...
>
>We started stocking this scope to go on the GM8 and G-11. The new OTAs are
>made to fit the G5 Celestron mount so they have the 2+" dovetail. Does
>anyone know how you interface these new OTAs to the GM8 or G-11 dovetail?
>Scott is on one of his 2-3 week sabbaticals so I can't ask him. I'm fairly
>certain he said he isn't making the 9.25" dovetails anymore and suggested
we
>cut off a C-11 plate.
>There has to be a better "no I don't have a machine shop" answer.
>Thank you
>Herb
>http://www.buytelescopes.com online astronomy and camera shop
>Anacortes Telescope and Wild Bird
Herb York
> Herb,
>
> What do you mean by "2+" dovetail? Is this the same dovetail plate used in
the
> Vixen GP mounts?
Well I measured it and it is actually 1.75" wide. I'm not sure if it the
same as the Vixen GP
Are you stocking the C-9.25" with the new CG-5 Celestron
> mount/alum tripod?
No.
>
> Thanks,
> Bob
Thank you
Herb
Carl Wilson
and later buy a Losmandy G-11 mount. Quick additional question: Is the
supplied G5 mount that comes with the G9 9.25" SCT sufficient for visual
work? Or will I want to upgrade to the Losmandy mount even before I get
into CCD imaging?
Carl Wilson
that the 9.25" SCTs are optically better than most SCTs due to being a
low production item, and that there is more testing and hand finishing
involved. Does anyone know if this is in fact the case?
Also, the tube seems to be rather long in proportion to it's diameter,
which would mean it would need a smaller secondary mirror, which would
help a bit as well.
I think I'm convinced. I'll go with the G9 9.25" SCT. Now if I can
find someone interested in a 10 year old Meade 826C? It better be
someone young and strong. :-) The only way I could get the mount even
reasonably stable was to add weight to the bottom of the pier. LOTS of
weight!
Tom Davis wrote:
>
> Carl,
>
> I owned a 10" LX50. The optics were quite good on the one I owned.
> The mount left something to be desired, though. The LX50 does not
> have PEC (Periodic Error Correction), and the drive suffered from
> a fast period error that made it impossible to use for CCD work.
>
> Also, the standard wedge was insufficient for any serious work. It
> was more stable with the super wedge, but quite heavy. I would
> recommend the LX200 series over the LX50 to anyone desiring to
> use the instrument for CCD use. I have found the CG9.25 to be
> a more satisfying instrument for my needs. The optics are of a
> consistent good quality (I have yet to hear of a bad 9.25. I have
> heard of more than one substandard LX50 8" and 10"), and the
> Losmandy GM8 is a definite step up from the LX50 fork mount in
> both stability and drive accuracy.
>
> Regarding the comments concerning the C8 problems, I sympathize
> with his problems, but I owned both the Celestar 8 and Celestar 8
> Deluxe versions, and they both worked just fine. You can get a
> bad unit in almost any scope model. I had a real problem with the
> LX50 electronics , but I understand Meade has addressed most
> of the problems I had experienced with mine. The reason for my
> recommendation is the lack of PEC and the better stability of the
> German Equatorial mount on the CG9.25.
>
Carl Wilson
Carl Wilson
Tom Davis
The design was originally one for a low production
run. What I mean is that the scope has no plastic in
it at all. Even the secondary holder and baffle are
metal. They have removed the micrometer from the
focuser, but the tube has not changed. The socket
for the micrometer is still there with a plate over it.
What sets the 9.25" apart from the other Celestron
SCTs is a longer F/Ratio primary. It is about F/2.25
versus the F/2 of the C8 and C11. This enables
Celestron to get better correction on the scope.
There is another issue in play here. It relates to the
masters used to create the corrector plate. Just
like the sand castings used for engine blocks, the
first correctors created off a master have a more
accurate figure than the later ones. Since the 9.25"
has not had a large production run as of yet, the
likelihood of getting a decent corrector plate still
exists. I have heard that the C8, C11 and C14
masters were recently redone, so this is not much of
a factor. The longer F/Ratio primary is a plus.
Thanks, Tom Davis
Carl Wilson wrote in message <386B1A21...@sonetcom.com>...
Tom Davis
I did some more testing with the CG5 with my 6" F/8
refractor on it last night. I upgraded the metal tripod
to wood, so this needs to be taken into account in
weighing my answer.
If I use the scope on grass, it works acceptably for
visual use. Damp times are in the several second
range for a light rap on the tube. Focusing takes a
little more time to get right due to minor vibration.
I attempted some piggyback CCD work with a
135mm camera lens. I was able to get repeated
2 minute exposures with no detectable guiding
error. This is not to say that the mount would work
for through the scope imaging, but the drive is
better than I expected it to be. Visual tracking was
fine, even at over 300X.
My answer is this. If you attempt to use the mount
with the supllied aluminum tripod, it will be shaky at
best. If you can get a hold of a set of wooden legs
(I got mine from Teletrade - originally from a GP
mount), the mount becomes useable for casual
visual observation, and at least with mine, piggyback
CCD or film photography.
You really have nothing to lose. If you buy the scope
and find the mount inadequate, the optical tube will
still have cost less after selling the CG5. I would
recommend upgrading the tripod at the very least
if you do decide to go that route. By the way,
Adorama is advertising a CG9.25 (Losmandy mount
version) without tripod for $1795. If put it on a pier
or purchased the Losmandy tripod for it, it might be
worth it.
Thanks, Tom Davis
Carl Wilson wrote in message <386B15FE...@sonetcom.com>...
Carl Wilson
with a mount like the G5 in the first place? They have to realize that
it's a poor match up. I know it's a means to keep the cost of a given
package down, but selling a good quality scope on such a shaky mount
doesn't make any sense to me. A poor mount is a frustrating thing to
deal with as I'm sure you know. Selling a setup that needs an immediate
upgrade?!
I was also looking over the Celestron CI-700 mount on the web. Decided
that wasn't an option. Doesn't look as good as the Losmandy and costs
about $100 more.
Carl Wilson
selling the Celestron 9.25" mounted on a Losmandy G8 mount (CG 9.25).
Price is about $2900 or so.
I understand that the Losmandy G8 mount is less preferable than the G11
mount, but would it suffice for CCD imaging?
"Tom Davis" <tda...@salisbury.net> wrote in message
news:84bfhn$1b37$1...@news.inc.net...
> Carl,
>
> If you are referring to the CG5 that comes with the
> G9, it would probably not have an accurate enough
> drive. I have the one that came with my CR150 6"
> refractor upgraded with wooden legs from a GP
> mount. It is vastly more stable, but not near so much
> as the GM8 (or Losmandy G9 - that is where I am
> confused - which one do you mean?). The scale
> of the CG5 head is not large enough for the 9.25"
> optical tube. The motor drive currently sold is fine
> for visual use, but not refined enough for CCD use.
>
> The Losmandy G9 or GM8 with the Celestron tripod,
> if remounted on a pier, should be more than stable
> enough. Drive accuracy should be OK for 1 to 2
> minute exposures unguided. Beyond that, an
> autoguider would be helpful. They do have an
> autoguider jack on the control panel. If you can get
> one that a dealer has sitting around after they have
> been discontinued by Celestron, this may be the
> most cost effective solution. If you can make a low
> cost pier for it, it might be the way to go.
>
> Hope this helps,
>
> Tom Davis
>
John Hagan
right now (10" LX50) which would be fairly simple to adapt to the
9.25" OTA. The LX50 base is stable, accurate and autoguider ready. I
think this one is in the $350US range right now, with a day to go.
Just a thought...
John Hagan
On Sat, 1 Jan 2000 14:06:24 -0600, "Carl Wilson" <ca...@sonetcom.com>
wrote:
>I've been searching around the web, and I see that some dealers are still
Tom Davis
Yes, it is will work for CCD imaging. You can do far better than the
$2900 price, though. I've seen GM8s for sale as low as $1375 new.
Add the cost of the optical tube, and you are still quite a bit lower
in price. I would expect to get a G11 mounted version for that price.
I use a G11 tripod on mine, so my results may not reflect that of
others using a GM8 with the standard tripod. It would be less stable
in a breeze. Also, the G11 has a 5.6" drive gear versus 2.8". It
would be even more accurate. If you are willing to go $2900,
consider the G11 version. It will eliminate any second guessing
yourself in the future. Ther is no such thing as too much mount
for CCD imaging, just too little.
Thanks, Tom Davis
Carl Wilson wrote in message ...
Tom Davis
you add the $400 for the necessary Super Wedge, and $295 for the
Meade field tripod, it is over $1000.00 - with no warranty. I owned
a 10" LX50. I found it highly frustrating for CCD use. The drive
suffered from serious periodic error with no PEC feature. An
autoguider may be useful, but with CCD imaging, one may not be
needed if the mount has a good, accurate drive. It may allow taking
multiple 2 minute exposures without guiding. My GM8 does allow
this.
The newer LX50 drivebases are reported to be better, but with a
used drive, it may well be the reason it is on AstroMart is due to
being and older unit. The reason for the sale being the owner
upgrading to a Losmandy G11 that give the tracking accuracy
not provided ny the older mount. Also, mounting the optical tube
would not be a straightforward as it seems. Tube diameters are
different, requiring shims, and the holes won't line up on the OTA
and the forks. It is doable, but not easily.
Thanks, Tom Davis
John Hagan wrote in message <386e67fa...@news.rcn.com>...
M. Hess
I feel lucky to have bought one of these last year withe original fork
mount for the following reasons, if there are still some out there you
may want to consider this option, esp. at the blowout prices that some
dealers had on them, there may be some left.
1. tracks beautifully, I have not done any serious deep sky photography
with my set up but for the amount of time needed for a CCD image I think
the fork mount would work fine.
2. Extremely easy to set up. It breaks down in the TWO pieces. Simply
set the tripod up outside, hoist the fork/tube assembly onto the wedge,
tighten up 2 screw/knobs - and thats it.(Wait for cool down) BTW,
hoisting this unit onto the tripod isn't a big deal, it doesn't weigh
enough to kill you.
3. As for being portable, I went to Shopko and bought a storage bin that
is approx. 36'x18'x18' for $20, lined it with foam - done. Easy to
transport and store. As you know the tube folds into the fork.
4. The optics are very nice. I bought this scope mainly for a deep sky
unit and am very happy - I was very suprised however when on excellnet
nights of seeing I was able to see more detail on the planets than ever
before - seeing conditions must be right on though.
Over all I am very happy I chose the fork mount. mh