Celestron G-9¼


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Brand and Model:Celestron G-9¼
Price ($USD):$1199.00
Type:Schmidt-Cassegrain
Attributes: un-checked Go-To un-checked PEC
Aperture:235mm (9.3")
f Ratio:f/10
Focal Length:2350mm
Finder:6x30
Electric Power:110V
Mount:CG-5 (EQ-4)
Tripod:Adjustable Aluminum
Weight (lbs):53 lbs.
Dimensions (w/h/d):
Description:Comes with 26mm Plossl (1.25 "), Star Diagonal, Visual Back, and Vibration Suppresion Pads. Also comes with Hand Controller.

The CG-9¼ telescope combines the unequaled optical excellence of a Celestron 9¼" Schmidt-Cassegrain telescope with an inexpensive German equatorial mount.

G-9 1/4 Specifications:
9¼ " (235mm) Aperture
Focal Length of 2350mm
Focal Ratio of f/10
Weight: 58 lbs.
Optical Tube Made in the U.S.A.

G-9 1/4 Standard Accessories:
Standard 1¼ " Accessories Include: 26mm Plössl Eyepiece (90x), Star Diagonal and Visual Back
6x30 Finderscope
CG-5 Mount
Sturdy Adjustable, Aluminum Tripod with Accessory Tray


Celestron's G-9 1/4 Page
Cloudy Night's Review
Ed Ting's Review of the C9.25
Todd Gross's Review of the C9.25

Vote Highlights Vote
Celestron G-9¼
I just got my second 9.25 the first one had a few bugs. Optics were average and the alignment of mirror in tube in relation to the secondary was poor. never could get dead on collimation and the front glass holding the secondary was over to one side to compensate for poor mirror alignment. Planets looked great but beep sky and faint stars were a problem never could get critical focus so I exchanged for another one and got very lucky this one is much better .Owning two other scopes and haveing extensive knowledge in optics I would have to say the scope is at least 1/6 to 1/7 wave or better the first one was around 1/4 to 1/5 kinda of a lemon in my opinion but for the money they are great scopes. The mount is some what light and the tripod worse. So I completely took it down and got rid of the pancake syurp grease they use and adjusted all bearings and worm gears with very good teflon grease and filled the legs with sand also put rubber washers at the inside and outside of the tray to leg connections. The screw is long and the gap is to much also drill a hole in the middle of the triangle tray and put a bolt and nut through the center and tray holder which already has a nice 3/8 hole at the center WOW tightened things up nicely not perfect but major improvement .Now this Photon Busting 9.25 handles 500+ no problem and the focuser on mine is silky smoth with the teflon grease job can turn with one finger and not wiggle the scope. Hope these tips will help you photon busters out their. Feel free to email me for help and other tricks not listed. Thanks By the way I heard rumor that the 9.25 was a parabloid mirror and not a spherical as all other cass scopes are. I beleave this is not true the secondary is a magnifiying curved type not flat. UPDATE just spent 3hours collimating this scope and I feel this scope is closer to 1/7 wave instead of 1/6 wave as I posted after adjusting and tweeking at both sides of focus at 600x this thing is absolutly perfect on collimation and the image just out of focus on both sides is identical and the closeing of focus back to critical focus is perfect with no spikes and no oblong star at very slight and I mean slight tweeking of focus knob. I have looked through some fine scopes of all types and I have never seen a scope go back to perfect focus with no spikeing or slight flare at the end just before critical focus. This is absolutly a keeper whish I could find another one this good I would buy it just to have one so well corrected whith no zones and stars that look like diamonds on black velvet. Not bragging just makeing a point that this is one of those rare production units that is a gem on optics and no image shift at 600x. I wish Celestron could be this consistant with all there scopes but cost would be a major factor for quality control this tight.GREAT SCOPE I would like to compare to say a 10 or 11 inch and wouldn"t be suprised to win on a 10 and good run on a 11 if not better.

Overall Rating: 9
Optics:10 Mount:6 Ease of Use:10 Value:10
Weight: 14 (Trustworthy Vote)
Date:
By: pjsviolin
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=88750

I think that the author of this review should take a course in logic, optics, and writing.
First, ALL Schmidt Cassegrain Telescopes have an aspheric corrector plate....NOT a lens in the classic sense. It is NOT an optical window. It corrects for the spherical aberration of the primary mirror, which is spherical.
Second, the primary mirror of all SCTs are spherical, have an F ratio of approximately 2, and use a curved secondary (I can't remember if it's spherical as well), in order to reach the ratio of F10. 
The primary CANNOT be a parabola. If it was the scope would be about two times longer than it is, with a secondary obstruction over 50% of the primary diameter.
NO modern cassegrains of ANY type or design uses a flat secondary....The optical tube would be longer than a newtonian with an F10 primary, and would be very short with and F2 primary, which by the way is the actual F ratio of an SCT primary mirror.
Yes, the C9.25 is a great scope...and deserves a 10...but it is not a different scope over any other SCTs. It's primary mirror is a bit longer in focal length than a standard SCT, about F2.4. Which lengthens the OPT tube, and allows a much higher quality primary mirror figure during manufacture.
One last note....occasionally the secondary mirror holder can loosen and shift during shipping. That is the cause of the corrector lens appearing to be "off to one side". This holder is easily repositioned, to achieve optimum optical mechanical alignment.
Otherwise, the first scope was probably a good one. I've owned 3 now, and they were all great performers.



>I just got my second 9.25 the first one had a few bugs. Optics were average and the alignment of mirror in tube in relation to the secondary was poor. never could get  dead on collimation and the front glass holding the secondary was over to one side to compensate for poor mirror alignment.  Planets looked great but beep sky and faint stars were a problem never could get critical focus so I exchanged for another one and got very lucky this one is much better .Owning two other scopes and haveing extensive knowledge in optics I would have to say the scope is at least 1/6 to 1/7 wave or better the first one was around 1/4 to 1/5 kinda of a lemon in my opinion but for the money they are great scopes. The mount is some what light and the tripod worse. So I completely took it down and got rid of the pancake syurp grease they use and adjusted all bearings and worm gears with very good teflon grease and filled the legs with sand also put rubber washers at the inside and outside of the tray to leg connections. The screw is long and the gap is to much also drill a hole in the middle of the triangle tray and put a bolt and nut through the center and tray holder which already has a nice 3/8 hole at the center WOW tightened things up nicely not perfect but major improvement .Now this Photon Busting 9.25 handles 500+ no problem and the focuser on mine is silky smoth with the teflon grease job can turn with one finger  and not wiggle the scope. Hope these tips will  help you photon busters out their. Feel free to email me for help and other tricks not listed. Thanks  By the way I heard rumor that the 9.25 was a parabloid mirror and not a spherical as all other cass scopes are. I beleave this is true the front corrector plate is just glass not a lens the secondary is a magnifiying curved type not flat.  I could be wrong but I don"t think so. UPDATE just spent 3hours collimating this scope and I feel this scope is closer to 1/7 wave instead of 1/6 wave as I posted after adjusting and tweeking at both sides of focus at 600x this thing is absolutly perfect on collimation and the  image just out of focus on both sides is identical and the closeing of focus back to critical focus is perfect with no spikes and no oblong star at very slight and I mean slight tweeking of focus knob. I have looked through some fine scopes of all types and I have never seen a scope go back to perfect focus with no spikeing or slight flare at the end just before critical focus. This is absolutly a keeper whish I could find another one this good I would buy it just to have one so well corrected whith no zones and stars that look like diamonds on black velvet. Not bragging just makeing a point that this is  one of those rare production units that is a gem on optics and no image shift at 600x. I wish Celestron could be this consistant with all there scopes but cost would be a major factor for quality control this tight.GREAT SCOPE I would like to compare to say a 10 or 11 inch and wouldn"t be suprised to win on a 10 and good run on a 11 if not better.

Celestron G-9¼
This may be the best value telescope today. All 3 models I've owned have proved to be superb performers. Easily beating out the 4 and 5" apo refractors I've owned, on planetary and deep sky detail and contrast. (I am NOT talking about background brightness) Jupiter shows detail within the bands and GRS. Festoons, streamers, blue ovals,...the list goes on. Saturn looks like a hubble photo on those rare steady nights. Globular clusters resolve easily to the core. Galaxies begin to show spiral arm detail you only read about and can only usually see in big reflectors.
One myth I'd like to dispence with is the one that says you don't need aperture in light polluted skies. Even in my Mag 4 backyard skies, I easily see much more detail in the larger scopes than small apos. No contest.
The 9.25 is my default instrument...meaning it usually gets the call when I need a quick use scope that I can use in goto mode, and still have enough aperture to resolve globular cluster, galaxy, and planetary detail without straining. It sets up quickly, and is almost light enough to use as a one piece set up, when mounted on a GP mount with HD tripod. The setup weighs in at 66lbs total. The optics are well corrected and well within the defraction limit...the latest one is about 1/7 to 1/8 wave undercorrected ala Suiter. The other 2 were 1/5th and 1/6th wave respectably.
Star images are extremely tight and refractor like, even at high powers. Planetary images are highly detailed, and contrasty...easily beating a Tak 128 Apo. Powers up to 500x can be used with comfort, with no breakdown. I never had the need to push it further. But, could have handled more. Nearly no image shift on the latest model...a bit more on the earlier 2. The finder is usable, but not great. Low power limits FOV to about 1.25 degrees. And it's nice looking but not as well finished as a Tak or AP. It does take time to cool down, but I get around that by getting it outside at sundown. It's cooled down plenty when it's dark enough to view. Even with the flaws it's argueably one of the best scope bargins out there. It' so good, I regret selling them soon after I do. This 3rd one is a keeper. I keep coming full circle.....25 scopes and $30,000 later I use the $1000 one the most. what does that tell you?
Additional note: The G5 Eq mount with this C9.25 was a lot more solid than I expected. Since it is a recent (3 month old) purchase, I suspect that these Chinese made mounts are much improved. Very smooth motions on both axis' with tight slow motion controls and almost no play. Once on a wood tripod, it was very close to a Vixen GPDX mount in stability......a best buy!!!

Overall Rating: 10
Optics:10 Mount:7 Ease of Use:9 Value:10
Weight: 10 (Trustworthy Vote)
Date:
By: Bernie
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=98233


Celestron G-9¼
This may be the best value telescope today. All 3 models I've owned have proved to be superb performers. Easily beating out the 4 and 5" apo refractors I've owned, on planetary and deep sky detail and contrast. (I am NOT talking about background brightness) Jupiter shows detail within the bands and GRS. Festoons, streamers, blue ovals,...the list goes on. Saturn looks like a hubble photo on those rare steady nights. Globular clusters resolve easily to the core. Galaxies begin to show spiral arm detail you only read about and can only usually see in big reflectors.
One myth I'd like to dispence with is the one that says you don't need aperture in light polluted skies. Even in my Mag 4 backyard skies, I easily see much more detail in the larger scopes than small apos. No contest.
The 9.25 is my default instrument...meaning it usually gets the call when I need a quick use scope that I can use in goto mode, and still have enough aperture to resolve globular cluster, galaxy, and planetary detail without straining. It sets up quickly, and is almost light enough to use as a one piece set up, when mounted on a GP mount with HD tripod. The setup weighs in at 66lbs total. The optics are well corrected and well within the defraction limit...the latest one is about 1/7 to 1/8 wave undercorrected ala Suiter. The other 2 were 1/5th and 1/6th wave respectably.
Star images are extremely tight and refractor like, even at high powers. Planetary images are highly detailed, and contrasty...easily beating a Tak 128 Apo. Powers up to 500x can be used with comfort, with no breakdown. I never had the need to push it further. But, could have handled more. Nearly no image shift on the latest model...a bit more on the earlier 2. The finder is usable, but not great. Low power limits FOV to about 1.25 degrees. And it's nice looking but not as well finished as a Tak or AP. It does take time to cool down, but I get around that by getting it outside at sundown. It's cooled down plenty when it's dark enough to view. Even with the flaws it's argueably one of the best scope bargins out there. It' so good, I regret selling them soon after I do. This 3rd one is a keeper. I keep coming full circle.....25 scopes and $30,000 later I use the $1000 one the most. what does that tell you?

Overall Rating: 10
Optics:9 Ease of Use:9 Value:10
Weight: 10 (Trustworthy Vote)
Date:
By: Bernie
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=80846


Celestron G-9¼
Best easielly transported large SCT
I like it.

Overall Rating: 9
Optics:9 Ease of Use:9 Value:9
Weight: 10 (Trustworthy Vote)
Date:
By: ritter
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=59096


Celestron G-9¼
I have had this scope for 15 months now, and after considerable effort and money, I am finally enjoying the OTA tremendously. The CG-9 1/4 package as sold by Celestron is not an enjoyable out-of-the-box experience. I strongly recommend that you purchase the OTA only, and mount it on a Losmandy GM-8 mount or better to start with.

After meticulously rebuilting the CG-5 mount, adding CG-5 drives and building a sturdy walnut tripod, there were no more vibrations. Finally I could enjoy steady images, but... the drives could not track accurately enough for even visual enjoyment with the load the mount was carrying after I had thrown away the cheap finder & diagonal, and added a 8x50 upright, focusing finder and a AP 2" Maxbright diagonal, Pentax eps, a dew shield (mandatory) and a telrad.

After giving up on the CG-5 mount, and putting the OTA and its upgraded accessories on a Losmandy GM-8 (and very precise collimation efforts)the OTA yields outstanding, steady images. Saturn and Jupiter in the early morning hours with steady seeing are simply awesome. M13 resolves nicely. The Orion Nebula is a religious experience. Double stars such as Almach and Alberio show beautiful color with clean splits. The double-double looks like two little pairs of headlights off in the distance. The maximum magnification that I regularly use is 225x with a Pentax 10.5 XL. With really good seeing the Pentax 7XL at 335x or almost 40x aperture can be used. The Pentax 21 XL at 112x and the 14 XL at 168x are my most used eps. Contrast is good, and stars are pinpoints. Side-by-side with large AP refractors, my 9.25 seems to hold its own. Only when side-by-side with 14.5" or 18" highest quality dobs such as Starmasters, etc, does their aperature makes deep sky detail become much more evident than the 9.25 can offer.


My rating is a 9 based on the the OTA being a 9.5 or 10 as SCTs go, but the junk that is supplied with the OTA does a disservice to the buyer by Celestron thus lowering the overall rating. IMHO, Celestron should offer the OTA with their 9x50 finder and a quality diagonal. But they don't...

The CG-5 and tripod are not factored into this rating, because they are insufficient for this OTA and one is better off avoiding them completely.

Overall Rating: 9
Weight: 9 (Veritable Vote)
Date:
By: Anonymous (xxx.xxx.5.54)
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=38251


Celestron G-9¼
I have the OTA ($950 from Shutan) and a G11 mount ($1895 everywhere). I threw away the finder and I use a Telrad.

My other scope was an ETX 125 and the G9 is so much better that I haven't used the ETX since. Brightness and detail blow away the ETX. Now, I've been comparing it against a Tak FSQ106 (4" APO; $3475) and on deep sky objects the G9 wins every time (more brightness and detail on every Messier object I've looked at). Wide field viewing, big bright clusters (like the Pleiades - not including their nebula) and some double stars are about the only areas that the Tak is preferable. The Tak FSQ106 and the G9 tubes are the same physical length.

I haven't been up late enough to compare the scopes on bright planets yet (besides Mars which is so low in the sky for me now that it's always fuzzy), but I suspect that the G9 will hold it's own very well. On Uranus, the G9's long focal length alone is enough to beat the Tak.

I rated it 9 instead of 10 because I get a little frustrated by the focus image shift. I guess the Tak wins there too.

On the Losmandy G11 mount, the G9 is rock solid and after spending 10 minutes to align it properly, images can stay centered in the eyepiece for hours.

I'm totally satisfied with the value of the G9 OTA.

Barnett

Overall Rating: 9
Weight: 9 (Veritable Vote)
Date:
By: Anonymous (xxx.xxx.244.228)
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=38249


Celestron G-9¼
I have had my 9.25 for about a month and I am already confident in its optical quality. The first night I had it out was at the Mt. Lassen Star Party, and I was very impressed. Under the crisp 8000 foot skies the star test was text book, the scope had even arrived in perfect collimation. The scope also has very little image shift, even during fast and far out of focus turns of the knob. Another virtue of the focus is how smooth it is. It is much smoother than any other SCT I have ever used. The Images that were delivered by the scope were stunning, M13 and M22 were pin-point, resolved straight to the core. I was also treated to a delightful view of mars filled with detail and contrast. The scope also provided a great view of comet A-2 Linear. The scope also performed very well on planetary nebulas, showing detail in M57 and M27. The only thing that the scope didnt do well on was wide field objects like the Veil, The Star Cloud and M8. The narrow field of view made the Veil kind of disappointing (especially since most people at the Lassen Star Party have 18 Dobs). The places were the scope really shown through was on star clusters and on the planets. The views of clusters, especially, were very much like a 6 APO (One of my friend up their has a 6 Starfire and we compared). It was clear that the biggest limiting factor were my Sirius Plossl eyepieces.
This was the good news so now for the bad. The standard mount is trash, and should be replaced, and then ground up for scrap metal (I upgraded to a CI-700). The standard 6X30 finder is a joke and useless (I use a Telrad). Finally the standard Diagonal is pathetic (replaced it with a 2 Orion Mirror Diagonal).
The basic gist of it is the optical tube is awesome but that accessories are trash. However considering the whole set up is $1400 it is acceptable to replace the mount, finder, and diagonal.

Overall Rating: 9
Weight: 6 (Veritable Vote)
Date:
By: Anonymous (xxx.xxx.154.137)
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=38246


Celestron G-9¼
The C-9.25 is definitely among the cream of the SCT lot, sharing the honor with the Takahahi 9" that I had many years ago; and that TAK was only slightly sharper. As a confirmed refractor and MAK man for years; Nikon APO, Zeiss APQ, Questars, Intes and Intes Micro Mak-Newts, have been in my stable. I add the C-9.25 to the best of them, no kidding. I have the OTA only and mounted on a very heavy duty Optical Craftsman head and permanent pier--the way to go with this tube.

Overall Rating: 10
Weight: 5 (Veritable Vote)
Date:
By: Anonymous (xxx.xxx.21.13)
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=38248


Celestron G-9¼
I bought my 9.25 3 weeks ago, before i was using a lx200 10" goto scope. The optics are compared to the lx200 the same, i think the 9.25 showed me a little more detail and was a bit more brighter than the lx200. I'm using the GP-DX mount and this is a good mount for it. In the future i'm thinking for buying the skysensor 2000.
Just viewed the moon a couples of days ago , and was surprising about the power the 9.25 have, i was viewing the moon with a 6mm eypiece and still clear pictures even when the air wasn't clear.
The other scope i owned was a celestron cr150-hd refractor, this is a nice scope but compared to the 9.25 it has some optic drawbacks.
So my conclusion is, i rate this a 10+

Overall Rating: 10
Weight: 4 (Unreliable Vote)
Date:
By: Anonymous (xxx.xxx.5.124)
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=38237


Celestron G-9¼
I bought this telescope because of the good things I have read about it and I have no regrets. I own several telescopes and this is my favorite. Of course if I had a 16" telescope or larger I'm not so sure I would be as excited(Aperture does rule). However, this telescope optically is magnificent. I have a 2" Televue Everbrite Diagonal and I use Televue eyepieces and find my images to be very crisp and bright both on planetary and DSO views. It is at the borderline of ease of portability. My only complaint as someone else indicated above is the mount. Although it is not terrible but it could be better. It has slight instability which can be annoying at times. Also, the scope comes with an inadequate 6 x 30 finder. I upgraded the finder to 9 x 50. I am only rating the optics which I feel is a great buy. I own 4 telescopes(1 sct, 2 reflector, 1 refractor) and have used other telescopes and again I like coming back to my c-91/4. in the 8-10 range you can't go wrong.

Overall Rating: 10
Weight: 3 (Unreliable Vote)
Date:
By: Anonymous (xxx.xxx.147.113)
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=38243

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