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
Date: 06/01/2002 03:21:09 am PST

Replies: 0

I love all telescopes and still own a 4" Tak, and it is a great scope...but the truth about performance has to be told...If I had to keep ONE scope it would be my EL12.5. Why, aperture wins. I believe that Scopes should be compared on a cost comparison, not strictly on like aperture. It's unfair to compare a $300 4" Newt to a $2900 4" refractor, even though many of them come pretty close in image quality. All my reflectors have handily beaten any 5" or less APO on planetary and deep sky detail. The only 2 saving graces for the smaller refractors is that they have quick cool down and can be used for extreme widefield use in excess of 3 degrees field of view. I owned 2 APs (Traveler and a 130) as well as 7 Taks (2 FS78, 3 FS 102s, and 2 FS128s), None even matched the performance of any reflector over 7-8" I owned regardless of make or manufacture, be it an SCT, Newtonian, or a MakNewt, whether on planets or deepsky. The price/performance ratio doesn't even come close. Many fail to remember that the most important consideration is aperture. As an example, even the 3 8" SCTs which I used to compare to two 5" Taks (these scopes were owned for nearly a year and directly compared side by side with the same premium eyepieces) beat out all these refractors on planets and deep sky detail, even in average seeing. I have never once seen more contrast or detail in the smaller scope, except when the seeing was exceedingly poor. Which was only about 20- 25% of the time.
If you consider that you can get a C9.25 with excellent optics with a computerized GP-DX mount for about $3300, it's a major value compared to about $2900 for just a Traveler optical tube. And it does beat it handily on all objects, except for those over 1 degree in size. But even then the intraobject detail is much higher and apparent in the larger aperture. As for ease of setup, it is about the same for both except that the Traveler can also be used on a large photo tripod for quick use.
I am absolutely convinced that refractors are perceived to perform better than reflectors because of: 1) Smaller aperture gathers less background light, and have darker backgrounds as a result...this is mistaken for higher contrast, particularly by novices and gives an aesthetically more pleasing image. The image contrast is higher in a larger telescope. 2) High quality refractors cool faster, and give excellent images within a short amount of time...large reflectors need a lot of cool down time, and are often not fairly evaluated at star parties because they did not reach thermal equilibrium 3) Comparisons are usually with reflectors that are not properly collimated, or cleaned 4) Most reflector owners of the cheaper dob and SCT variety use less than premium eyepieces, where a Tak or AP owner wouldn't even consider using less than premium ones on such an expensive instrument. Premium eyepieces can even improve a dept. store scope!!! 5) Lastly, the comparisons are made to less than premium instruments. An EL11, costs about $2600 shipped, mount and all. Add a dob driver and computer and your at about $3600. Considerably less than the $6-7000 for a premium 4" refractor setup. And the 11 beats it handily on every object under 1.5* in size.

Overall Rating: 5
Optics:10 Ease of Use:9 Value:4
Weight: 10
Date: 05/16/2002 06:06:44 pm PST

Replies: 2

I've owned 3 C8s so far. All have performed superbly on all objects, both planets and deep sky. Even when compared over several months with Tak and AP 4 and 5" apos, all 3 C8s won on all objects, except for the largest clusters. All were 1/4 wave or better using Suiters star test. Nice finish, really a bargin if you think about the cost of one of these compared to the high end apos, makcass, and maknewts out there.
Here is another myth, central obstruction size is the LEAST important criteria when it comes to object contrast. Aperture is the most important, followed by optical quality, then the atmoshere....obstruction is dead last. Now I'm not here to say that it doesn't decrease contrast with low contrast features, yes it does, but you also get an INCREASE in contrast with high contrast and course detail, in an object. It depends on which part of the MTF curve you are looking at. And it only applies when you compare like aperture scopes. Any 8" beats a 4"... the laws of physics can't lie.
We compared my GPC8 to a 7" Mac Newtonian on both planets and deep sky objects over 12 observing sessions. The conclusion was unanimous amoungst the 6 of us doing the testing...The C8 had near identical contrast and detail on planets...and was brighter and had better resolution on DSOs. There was virtually NO difference between them...except price (The C8 with mount) cost about 2/3rds as much as the 7" mac newt OTA alone. Plus, the GPC8 is very portable. Great for city dwellers who need to travel to dark skies.
The GP mount and tripod, was very stable and tracked extremely well. Very little periodic error could be found when doing long exposure astrophotography. The polar finder scope was extremely accurate...as was the setting circles. I never had any trouble using them to find difficult DSOs, once calibrated. The mount was smooth, solid, dampened very well, and is relatively inexpensive. They can easily hold up to 20lbs and even more with a heavier tripod.
After owning 40 scopes, this is probably the best overall value I ever owned.
If you are thinking about getting one....do it, especially if you are only going to own one scope. Very versitile. Don't let anyone tell you that Schmidt Cassegrains are the worst....no way! Aperture wins...especially over anything under 6"s. The laws of physics can't be denied.

Overall Rating: 10
Optics:9 Mount:9 Ease of Use:8 Value:10
Weight: 10
Date: 04/10/2002 07:34:55 pm PST

Replies: 0

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
Date: 04/07/2002 11:23:52 am PST

Replies: 0