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Telescope Review: Celestron C8 (Celestar 8)


1998-08-22 by Rick Towns

Telescope: Celestron C8 (Celestar 8)
Type: Catadioptric
Description: 203mm f/10 Schmidt-Cassegrain, 6x30mm finder, 25mm Kellner eyepiece, $1895 CAD.
Setup: This was my first serious telescope. I bought it way back in 1997 before GOTO became all the rage. The only options I had on my scope were a dew sheild and a Telrad. This is the C8 series that comes with the "wedgepod" - the tripod and wedge are integrated in one unit. The scope has a built in RA motor that is powered for up to 40 hours by one 9V battery. It includes slow motion knobs on both axis as well as setting circles. The 90 degree star digaonal interfaces with a 1.25 inch visual back.
Appearance: C8 was a black tube beauty. It was very well made, with a metal housing at the rear of the OTA. The big Schmidt corrector at the front was equipped with StarBright coatings, and they appeared to be very evenly applied. The secondary housing had a removable orange cap to provide access to the collimation screws. I only had to adjust the collimation a few times over the 4 years that I owned this scope. The fork mount is also metal and is very rugged, with a carry handle on one side. The base is a combination of metal and plastic, with some ports for uplinking a hand controller and other accessories. The wedgepod is also an all metal affair, with three sturdy tube steel legs and rubber pads at the ends. Overall the appearance is very good and the construction is also very good.
Performance: With this scope being almost double the aperture of my venerable 4.5 inch Newt, I was startled at how much brighter everything was in the eyepiece! This scope just drinks in the deep sky stuff as well as providing good views of the planets. Optically, I'd rate this scope as good as any other 8 inch scope I've owed/used. However, with it being my first serious scope, I was unable to adequately test the performance of the optics. As I recall, the stars only showed as pinpoints when the f6.3 focal reducer was used. When not used, star images tended to be small flaming balls instead of pin points. In retrospect, I'm sure this was more a case of not letting the scope cool down properly as opposed to any problem with the optics. The supplied 25mm Kellner eyepiece did an adequate job, but things looked very good through my Tele Vue 20mm Plossl. Lots of detail on Jupiter was evident, although I never saw the GRS, as it was going through a very dull phase during the late '90's. The most striking thing I remember about the C8 was it's ease of use compared to my EQ mounted Newt. With the Telrad in place, it truely was a point and look operation - targets were tracked down much faster, which meant more time viewing and less time looking. April and I even employed the setting circles one night to successfully haul in Uranus and Neptune - it was a delight to see their non-stellar discs in the eyepiece!
 
This is probably the most portable and easy to set up 8 inch SCT on the market. The wedgepod folds down and sets up in a matter of seconds - no legs to adjust or spreader to tighten. I often attached the forks/OTA with just one hex bolt (instead of all three) when taking a quick peek. Overall the scope was very easy to use and provided pleasing views.
Pros:
  • Sharp SCT optics
  • Easy to set up and use wedgepod
  • Very easy to target objects with fork mount set up
  • Reasonably large aperture in a portable package
  • Entire setup was very egronomic - the wedgepod even had a convenient tray to store eyepieces & Barlows in!
  • Slow motion controls were buttery smooth
  • RA motor tracks true and is super quiet
  • 9V battery really does last 40 hours!
  • Fantastic platform for simple astrophotography
Cons:
  • Wedgepod provides no height adjustment
  • Long cool down time for optics to perform their best
  • Constrast isn't as good as similarly sized Newts
  • Some play in the focuser as the mirror can stick at some angles
Conclusions: Overall this is an awesome scope. I believe it's out of production now, but many are available on the used market for a good price. The optics are rugged and provide very pleasing views. The overall operation of this scope is probably the easiest of all scope types - even including Dobs!
 
The bottom line? Recommended (Great optics in a portable, easy to use package).
Reviewer: Rick Towns
Review Date: 8/22/1998

 

My name is Rick Towns and I am an amateur astronomer and computer programmer from Canada. This is a collection of interesting posts I've gathered over the years.