Celestron C8 Overview and History
By Ed Ting
Celestron Advanced Series C8-SGT 203 x 2032mm Telescope. $2,455.95 $ 2,455. FREE Shipping by Amazon. Temporarily out of stock. Celestron C9 1/4 A Telescope StarBright XLT 91027-XLT. This is a 1980's-era Celestron orange C8 with stamped forks, serial number 31548. It is in excellent cosmetic and optical condition, with no signs of fungus or discoloration on the corrector, primary mirror or secondary mirror. A bit of dust and some cleaning swirls on the corrector that do not affect views. Focuser is smooth with minimal image shift.
Updated 3/4/11, 3/7/11
A modern (2010 NexStar version) Celestron C8
The Celestron C8 Schmidt-Cassegrain is one of the longest running continuously produced telescopes inhistory (perhaps only the Questar has been around longer.) In 40+ years of production, while the mounts and accessoriesaround the scope have changed and advanced (sometimes dramatically) the opticaltube itself has changed remarkably little. Celestron started out in the1950s as a branch of Valor Electronics, a company selling electronics to theaerospace industry (Valor is still around today, and is now known as Pulse,Inc., which sells electronic components.)TomJohnson, who founded the company, built telescopes as a hobby. A shorttime later, in 1964, hefounded Celestron as a division of Valor. Early SCTsranged widely in aperture from 4' all the way up to 22'. Theseare extremely rare today. Around 1970, Johnson teamed up with Alan Hale, abusinessman, and the modern Celestron company we know today was formed..
Tom Johnson and an early C8
In 1970, Celestron introduced the C8, an8' f/10 Schmidt-Cassegrain. It sold for $795. The scope was animmediate success, offering high quality optics in a compact package that wasreasonably affordable. This was during a time when almost all telescopeswere handmade Newtonian reflectors. It took the resources of a largecompany to mass produce Schmidt-Cassegrains, which were much more complicated tomake. Celestron telescopes became widely popular not only among amateurastronomers, but with institutions and the government. The original lineof Celestron telescopes contain what would be considered today an odd range ofapertures: There was a C10, a C12, a C16, and a C22(!) Through the years,Celestron settled into the range of apertures familiar to amateurs today - the5' f/10, the 14' f/11, and later, in the late 1970s an 11' f/10was added. The smaller C90 Maksutov filled in the lower end of therange. There were also 5.5 inch, 8 inch, and 14 inch Schmidt cameras inthe line.
Original Celestron company logo
The C8 scopes at the time came in one compact23 lb swing-through unit. The drives were AC powered. They werefork-mounted, with setting circles on the RA and Dec axes. The tubes werepainted a distinctive orange color, which is still being used today (newer tubeshave a deeper iridescent shade of orange.) Original C8 tubes usedlead-based paint, so be careful around it if you own one. Since the unitwas technically Alt-Az as supplied, the entire assembly had to be mounted on a awedge and a tripod to achieve proper polar alignment. This generallydidn't pose a problem for the lighter scopes like the C5 and C8, but the entirecontraption got a little unwieldy as you got to the 11' and 14'models. Polar alignment was accomplished by turning the tube 180 degreesand sighting Polaris through the finder. This was awkward, andmechanically precarious on the larger models. As the industry gradually switched over to DC, Tim Gieselerintroduced the Accu-Trak drive corrector system. Gieseler went on to foundOrion Telescopes and Binoculars. Eventually, setting circles disappearedfrom the scopes entirely.
What do you mean 'The RealUniverse?' You mean Star Trek wasn't real??
Through the inflation-prone 1970s and early1980s, the prices went up steadily. In a May 1981 price list, the baseprice for the C8 assembly was $1050. Unless you had a mount for it (whichhardly anybody did back then) the scope was pretty much useless without thewedge and tripod. The wedge was $60 and the tripod was $150, and if youwanted the enhanced coatings, you had to fork over another $100. Aninteresting side note: The Consumer Price Index (CPI) from 1981 to 2009 rose bya factor of 2.33. So your $1360 C8 package is $3168 in 2010 dollars! Consider that right now you can get a NexStar 8 from most retailers for about$1100. If you really wanted to go to town, a C14 with coatings, wedge andtripod sold for $6550 - a cool $15,261 today (computer controlled C14s sell for$9000 - $11000 today depending on what you get.)
Celestron Price List from May 15,1981
Neither Meade nor Celestron (nor Criterion/Dynamaxfor that matter) were exactly shy in their advertising during this period (late1970s - early 1980s.) I still have a collection of brochures from that eraand I still get a chuckle out of reading them. Check out this obviouslybiased example from a 1985 Celestron catalog. It takes thereflector/refractor/catadioptric comparison chart to new heights:
The era featured the now-famous 'Celestrongirls.' These ads were not subtle. At the same time,Meade was going in the opposite direction with their ads, often showing nerdyscientists in white lab coats.
This ad makes no pretense about what youmight do with that 750 mm lens
I'm a C8 and I like long walks on thebeach...
Come hither; there'sa Celestron Newtonian in it for you!
In contrast, Meade was portraying theirtelescopes as serious scientific instruments
As a company Celestron went through major changes startingin the 1980s. After the frenzy of the arrival Halley's Comet in 1986,sales languished. Celestron had already been sold to a Swiss company backin 1980 and by 1985 or so, quality began to slip. In 1998 Celestron wassold to the dreaded Tasco, which itself folded in 2002. Then, afteroperating by itself for a few years, Celestron was acquired by the Chinese Syntacompany in 2005. At first this raised some eyebrows, but overall, thealliance has been good. Quality has come up, and there are plenty of newproducts from the new Celestron company (I'm very pleased, and pleasantlysurprised, at the quality of my C6, and the new C90s are a steal.)
Variations:
Celestron C8 Serial Numbers
The C8 has been through so many incarnationsthat it's hard to enumerate them all. The original C8 has remained in thelineup since the beginning, but there have been a slew of offshoots:
- The original C8. These were made more or less continuously from 1970 to about 1982-1983. $800 - $1000 new, depending on vintage.
- The Super C8 was an upgrade to the standard C8. It was largely seen as a response to Meade's 2080 SCT, introduced in the early 1980s. You could get one in orange or black. One attractive selling point of the scopes was the Byers worm gear drive. It was still fork and wedge mounted. The Starbright coatings were an option, until Celestron introduced the Super C8 Plus a couple of years later, which had the coatings as standard. These were made in the mid 1980s. $1200 - $1500 new, depending on options.
- The SPC8 was the first equatorially-mountedC8, using a Vixen Polaris/Super Polaris mount. They were popular from the mid 1980s to the early 1990s. The retail prices ranged from $1000 - $1300 depending on options. You still see some of these around.
The Compustar was the first Goto C8,introduced in 1987. It was ahead of its time. Maybe a bit too aheadof its time. There have been accuracy and reliability issues. It's mostly a curiosity now, but the model does have somedevotees. About $3500 new. If you get one, be sure yours has the Y2Kcompliant mod.
The Powerstar C8 was the first DC powered C8, made in response to Meade's then-new LX3 models in 1987. The big innovation here was the DC drive system. There were many versions and this model was produced for nearly 10 years.
- The Ultima C8 (1988) had a number of incremental enhancements, including a rechargeable lead acid DC battery (later replaced by a simpler 9V battery) sturdier mount, and upgradedelectronics. Later versions have PEC. Very desirable today if you don't want or need computers. Expensive for its time at around $2400.
- The Ultima 2000 from the late 1990s was the first computercontrolled C8. The 'U2K' was expensive at $2700. Later versions were Fastar compatible.
- The Celestar 8 was a back-to-basics non-computerized C8. Later versions were Fastar compatible. Otherwise, it retained the traditional wedge and fork mount. The tube was black and the secondary had an orange cover. From about 1996 to about 1999. The scopes sold for $1100 - $1300 new.
- The NexStar 8/se, first introduced around2003, was the first of the single-sided swing arm ('one armed bandit')computerized scopes. Later units have GPS. These were given a facelift in the late 2000s (to 'SE' status) andwere given upgraded electronics. The original 2003 version had a gray tube. Newer 'se' units havethe orange tube. The scopes initially sold for $1700, but prices have dropped to around $1100 in 2011.
- The CPC 800 was/is a GPS enabled C8. The CPC 800 was fork mounted with a black tube. These looked somewhat like the original C8s, but theforks were much thicker and bowed outwards. As a result, they lookunusually large for an 8' SCT. These are still sold today. About $2000 new.
- The Edge 8 models feature excellentcorrection at the edges of the field for astrophotographers. The tubes arelight gray. Expensive ($2000 - $2500 list.)
What to look for in a used C8:
Because so many of them have been made, usedC8s are not hard to find on the used market. Most are quite usable todayprovided that they have not been abused. When considering the purchase ofa used C8, it always helps to see the scope in person. Pictures help, butthere is no substitute for seeing and touching the scope yourself. Inreviewing the comments below, you'll see that many of the problem areas havenothing to do with the optics, which are relatively robust. It's themount, drives, and accessories that you need to be concerned about. Inbrief, here is a checklist.
- Check to see if there is any obviousphysical damage. If so, move on. There are plenty of fish in thesea.
- If the scope was made between 1985 and 1990 (ie, the Halley's Comet era) be extra cautious. These were not good years. Powerstars seem to be especially suspect.
- Conduct a quick star test. With aneyepiece in the diagonal and the telescope pointed at a star, go in and out offocus. If it's daytime, catch a glint of light off something. In apinch, point a flashlight at the scope from far away. Any opticalaberrations should show up under this sensitive test.
- While you're doing the star test, see ifthe image shift is acceptable to you (there will almost certainly be some imageshift.) And while you're at it, see if the scope is collimated.
- Do the coatings look good? Note thatfaded or dirty coatings are not by themselves a reason to reject the scope, ifit looks good otherwise.
- Is the optical tube fork mounted or railmounted? These days, a rail mounted OTA is a definite plus. Olderfork mounted tubes can be drilled for Vixen-style dovetails, but this is notalways a simple operation. Are you sure you know what you're doing? People have accidentally drilled into the primary.
- If it's one of the old fork mount units, doyou plan on using the clock drive in it? If so, you need to check it out. Clock drives sometimes sit unused for decades. With the scope polaraligned, look at an object near the horizon. Does it track? If so,swing the scope to the other horizon. If it still looks OK, stop and askyourself again - Are you still sure you want to deal with a wedge mounted, forkmounted C8?
- Older controllers like the Accu-Trak (andeven ca. 2000 Celestar hand controllers) are becoming very rare. Be surethey work. If the owner has an spare, that's a plus. If you're looking at a Celestar with a missing or broken hand controller, check to see that the manual controls aren't too stiff for your taste (good luck with that one!)
- It's an unfortunate fact of life that fancyGoto electronics fail. Don't pay too much extra (if any) for acomputerized mount. Some of the original Ultima 2000s are getting to be 15years old already. If you are buying a Goto mount with your scope, assumeit will fail. Now price it accordingly.
- In any paddle-controlled scope, there willbe drive backlash. Check to see that the amount is acceptable to you.
- How much is it worth? This is atricky question to answer. Assuming you are not dealing with one of thenew expensive Edge OTAs, used prices for optical tubes seem to be settling in the $250 - $500range, depending on vintage, condition, and what accessories the owner iswilling to throw in. This is a rough guideline only! Yourexact situation may be different.
My own preference is to find a clean, usedOTA with good optics and rail attached. The rail gives me flexibility touse a variety of mounts. The scope will likely outlast the mount, so youneed the ability to remount it as needed.
-Ed
End Celestron C8 HistoryHey, Guys. I just noticed what happened at Astronomyforum, and moved here. Good to see familiar people!Celestron Super C8 Plus Manual
I have several C8 SCTs, including a couple for my experiments as you may know. But, I happen to have one of which I had never opened up the tube. Well, I moved recently from a house I had lived in for 45 years. Accumulated tons of stuff, so the move was a big deal! Somehow, some specks got into that scope. Had to open it, so it got a full bath tonight.
Removed the plate, marking the plate and tube carefully as always. The number was slightly off the 3:00 position, so the serial number on the secondary holder did not point exactly right either, but they are not always perfect. However, about a quarter way around the plate from there, I noticed some scratch marks near the edge. Looking closer, it was a number that had been scratched through!! Never seen THAT before. I forgot to see if I could tell if that number matched the other number. If the numbers are different, I wonder if this corrector plate was transferred at the factory from another scope returned due to damage in shipment or something, and run back through the assembly line.
I have exchanged plates on a couple of my scopes that appeared to work fine, but the scratch marks on the donor plates did not end up in the normal factory position in the different tubes of course.
Take care.