Celestron flavours

I'm presently considering a Celestron 9.25" SCT, and am curious about the
practical differences between the Advanced series and the CGE series. The
price difference is huge. I would buy a non-GOTO if I lived in the country,
but it's a huge convenience when you live in a light polluted location. Is
the EQ-5, as found on the Advanced series, the right mount for this scope,
or is it "underpowered", so to speak?

Thanks


--
Bob

Travel and Astronomy Photos
http://www3.sympatico.ca/bomo

bob wrote:
I'm presently considering a Celestron 9.25" SCT, and am curious about the
practical differences between the Advanced series and the CGE series. The
price difference is huge. I would buy a non-GOTO if I lived in the country,
but it's a huge convenience when you live in a light polluted location. Is
the EQ-5, as found on the Advanced series, the right mount for this scope,
or is it "underpowered", so to speak?


Hi:

Me? I'm through buying non-goto scopes. ;-)

As for the CGE vice ASGT, the CGE is a much heavier duty mount, and is
certainly advisable if you're considering heavy imaging, especially
with the C11. OTOH, the ASGT's CG5 works very well...surprisingly well
for the price.

Peace,
Rod Mollise
Author of:
Choosing and Using a Schmidt Cassegrain Telescope
and
The Urban Astronomer's Guide
http://skywatch.brainiac.com/astroland
The Annual SCT User Imaging Contest is Underway!
http://www.rothritter.com/contest/2006/

"RMOLLISE" wrote in message
oups.com...
Hi:

Me? I'm through buying non-goto scopes. ;-)

Oh no, please don't....!


As for the CGE vice ASGT, the CGE is a much heavier duty mount, and is
certainly advisable if you're considering heavy imaging, especially
with the C11. OTOH, the ASGT's CG5 works very well...surprisingly well
for the price.


I do like the solidity of the CGE, and I do need a good mount for
photography, but if I can get away with spending $2000 less for something
almost as good, I'm game. I may see if my local shop has them for rent. For
visual observing, anything will do so long as it tracks in RA and doesn't
wiggle too much when I focus, but I think I'm done with fork mounts.

Thanks

bob wrote:
I'm presently considering a Celestron 9.25" SCT, and am curious about the
practical differences between the Advanced series and the CGE series. The
price difference is huge. I would buy a non-GOTO if I lived in the country,
but it's a huge convenience when you live in a light polluted location. Is
the EQ-5, as found on the Advanced series, the right mount for this scope,
or is it "underpowered", so to speak?

Thanks



For visual use the Advanced Series GT-C9.25 works just fine (I had one).

That said, EQ mounts are really only beneficial (required) for imaging.
If you have NO intentions whatsoever in getting into imaging, it might
make more sense to look at a CPC-925 for convenience and ease of setup
(has no counterweights, requires no polar alignment, just a tripod and a
fork mount, no need to be able to even see the celestial pole).

With _that_ said, the AS-CG5-GT mount is capable of imaging with a 6" F5
Newt or an 80mm F7.5 (Orion 80ED) refractor and a DSLR (two relatively
inexpensive ways to experiment). So, if you go with the C9.25 on the
AS-GT mount, you can use it for imaging with smaller scopes. That's not
something that you can do with the fork, without a wedge and a piggy
back arrangement, which gets costly in a hurry.

Good luck.
Stephen Paul

On 2006-07-21, bob wrote:
I'm presently considering a Celestron 9.25" SCT, and am curious about the
practical differences between the Advanced series and the CGE series. The
price difference is huge. I would buy a non-GOTO if I lived in the country,
but it's a huge convenience when you live in a light polluted location. Is
the EQ-5, as found on the Advanced series, the right mount for this scope,
or is it "underpowered", so to speak?

I do believe the 9.25" SCT is too large for the EQ-5. I have
put a C8 on an EQ-6 with good results. The 9.25" SCT is about
twice as heavy as a C8, but I think the EQ-6 can handle it.
The next step up would be a Losmandy G-11 or the Celestron
CGE.

Bud

That would be disappointing, since Celestron sells the 9.25 on an EQ-5
mount. If the mount is not up to the task, they shouldn't sell it as a
package.


--
Bob

Travel and Astronomy Photos
http://www3.sympatico.ca/bomo




"William Hamblen" wrote in message
...
On 2006-07-21, bob wrote:
I'm presently considering a Celestron 9.25" SCT, and am curious about
the
practical differences between the Advanced series and the CGE series.
The
price difference is huge. I would buy a non-GOTO if I lived in the
country,
but it's a huge convenience when you live in a light polluted location.
Is
the EQ-5, as found on the Advanced series, the right mount for this
scope,
or is it "underpowered", so to speak?

I do believe the 9.25" SCT is too large for the EQ-5. I have
put a C8 on an EQ-6 with good results. The 9.25" SCT is about
twice as heavy as a C8, but I think the EQ-6 can handle it.
The next step up would be a Losmandy G-11 or the Celestron
CGE.

Bud

"bob" wrote in message
...
That would be disappointing, since Celestron sells the 9.25 on an EQ-5
mount. If the mount is not up to the task, they shouldn't sell it as a
package.
--
Bob
It is OK, for _visual_ use, but for imaging, is 'undermounted'. The same
is true of the C11 (which weighs about the same), and the C10 NGT.
The current ASGT mount, performs very well for the money, but you do not
get a good heavy duty imaging mount for this sort of money...
The latter tripod, and improvement in the gears on this mount, make it one
of the best 'value' mounts around.

Best Wishes

Travel and Astronomy Photos
http://www3.sympatico.ca/bomo




"William Hamblen" wrote in message
...
On 2006-07-21, bob wrote:
I'm presently considering a Celestron 9.25" SCT, and am curious about
the
practical differences between the Advanced series and the CGE series.
The
price difference is huge. I would buy a non-GOTO if I lived in the
country,
but it's a huge convenience when you live in a light polluted
location.
Is
the EQ-5, as found on the Advanced series, the right mount for this
scope,
or is it "underpowered", so to speak?

I do believe the 9.25" SCT is too large for the EQ-5. I have
put a C8 on an EQ-6 with good results. The 9.25" SCT is about
twice as heavy as a C8, but I think the EQ-6 can handle it.
The next step up would be a Losmandy G-11 or the Celestron
CGE.

Bud

On 2006-07-21, bob wrote:
That would be disappointing, since Celestron sells the 9.25 on an EQ-5
mount. If the mount is not up to the task, they shouldn't sell it as a
package.
That never stopped them before.

bob wrote:
That would be disappointing, since Celestron sells the 9.25 on an EQ-5
mount. If the mount is not up to the task, they shouldn't sell it as a
package.



To put this into perspective, I actually had no major grievances using
the C9.25 on an older Celestron/Vixen GP mount with wood legs and manual
slow motion controls (no motors) for globular and galaxy observing (180x
and 97x). (It was certainly easier to carry out fully assembled than
with the AS-CG5.)

Now consider that the AS series CG5 is more robust than the old, tried
and true Vixen GP. It's plenty enough mount for the C9.25 for visual
deep sky use.

For planets it would be nice to have a motorized focuser for powers over
200x to reduce vibrations while critical focusing, but that's almost
always true without _over-mounting_ any scope.

I also had the C9.25 up on a G11 and it was rock solid (aka over mounted
for visual, and well matched for imaging).

The C11 on the other hand is certainly over the limit for sensible use
on the AS-CG5, except maybe at low powers.

"bob" wrote in message ...
That would be disappointing, since Celestron sells the 9.25 on an EQ-5
mount. If the mount is not up to the task, they shouldn't sell it as a
package.


Hi Bob,

IMHO the EQ5 mount is adequate (at least for my Celestron 8" Newt) for
visual work only. Admittedly the longer tube of the Newt makes harder work
for the mount but 8" Newt vs 9.25 SC would have (ballpark) similar inertia.

HOWEVER- the trap NOT to fall into (and I did) is to get the EQ5 and then
retro-fit Celestron's dual- (or single-) axis motor drive. This option
seemed attractive to me, but the build quality of the retro-fit is woeful. I
can't say this too many times or loudly enough. When the retro-fit kit
arrived I attempted to fit as per the (somewhat brief) instructions. Some
gear parts were so inaccurately machined that they simply would not line up.
I wasted far too much time sourcing other shims and washers etc to get the
parts aligned. Once lined up, the periodic error is enough to make even
low-powered visual use somewhat frustrating, and high-powered views give
stars appearing and disappearing like yo-yos. Photographic work is
impossible. The hand-controller also had a fault - the Northern/Southern
hemisphere slide switch would only maintain contact once it was taped into
position. I sent this part back to my supplier who kept it for 8 weeks then
sent it back (unchanged). (This is a local distributor gripe - *not* a
Celestron gripe, but the switch problem should not have made it past quality
control).

I have since discarded this kit, and the mount now serves in the original
unaltered mode as a reasonable hand-guided EQ5. It is very stable (if a
little heavy), and vibration damping is very reasonable (and I don't use
vibration suppression pads, although I hear of many who swear by them).

Good luck with your purchase.

Al