Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

Return of the Prodigal Celestron

This topic has been archived. This means that you cannot reply to this topic.
8 replies to this topic

#1 Clive Gibbons

Clive Gibbons

    Mostly Harmless

  • *****
  • topic starter
  • Posts: 16724
  • Joined: 26 May 2005

Posted 13 November 2005 - 11:27 PM

Nostalgia can be a powerful thing.
Waaaaaay back in the mid '80's, long before GOTO robo-scopes, cheap CCD imaging and the Internet as we know it,
I enjoyed a big, honkin' Celestron C-11. It wasn't fancy, sophisticated or light weight.
The brute was great for long exposure astrophotography. Smooth, accurate drive. Rock o' Gibraltar tripod and wedge.
After two years of faithful service, I suffered a lapse of judgement and sold it. The reason? It wouldn't fit in my newly acquired small, pseudo-sporty 2-seater vehicle. OK, this *was* the mid '80's, so perhaps the brain cramp was understandable.
Change of lifestyle. More into Duran Duran than polar alignment. Movin' on and less interested in the charms of a big SCT.
However, I kept in touch with the buyer of my dearly departed scope and reminded him that if he ever wanted to
resell it in the future, I'd appreciate first refusal. Eighteen years later, he still hadn't called back, so the ol' C-11 remained a pleasant memory perhaps never to be relived...until very recently.
A friend of mine visited a local astronomy shop and spotted a used C-11. In fact, it was just arriving in the store, while he was browsing around. This sounded tempting. It had the massive wedge and tripod shared by older-style C-11's and C-14's. The optics looked clean. The scope was cosmetically excellent for it's vintage. The price was reasonable.
Could it be the same C-11 that I sold nearly two decades ago? From the description and the accessories included, it seemed like a doppelganger. Nostalgia won the day. Here was a chance to own "the scope that got away"! The deal was quickly done...
Once I examined the scope more closely, I realized it wasn't the exact same C-11 I owned in the '80's. That was slightly disappointing, but this unit was in even better condition than my old one. It obviously hadn't been dragged around the countryside
on deepsky photography excursions. Almost no dings, scuffs or scratches on anything. The optics were sparkling.
After a few nights of observing with the "prodigal C-11", the joys of it's performance and the drawbacks of it's bulk have been rediscovered. Images are bright! The focus action is smooth and there's very little image shift. It takes a while to cool down. Two to 3 hours seems to do the trick, if it's not overly cold outside and the ambient temp doesn't keep dropping too fast.
Big scopes are affected more by bad seeing. The C-11 is no exception. It's not a killer scope for tight doubles when the air is boiling. Did I mention the images are *BRIGHT*!? One look at the gibbous Moon just about fried the ol' eyeball.
Vega needs a neutral density filter. And that's at 117x! After using small scopes for so many years, I'd forgotten what this much light gathering power could do.
The scope keeps it's collimation well. I haven't adjusted anything and it survived nicely after a pretty bumpy ride from the dealer. If the seeing ever steadies sufficiently, perhaps a tweak or two will result in perfection, but it looks very good at this point. No astigmatism. Intra and extra-focal star images appear very similar.
Set-up is fairly easy. It would be easier if I was Scott Beith. Hauling the 60 pound OTA and fork mount combo onto the equatorial wedge requires some finesse. There are two guide pins on the wedge that slot into the bottom of the drive base. If you don't align things properly, you'll end up futzing around with a ton of scope in your rapidly tiring arms, praying that someone will come along and help.
It's a good thing to have a buddy assisting with that part of the assembly.
This scope came with a JMI moto-focus, which my original C-11 didn't have. The moto-focus is a useful accessory. Zero vibration while focusing.
The original 10x40mm straight-thru finder is sharp and has decent eye relief. The scope sits high enough on it's tripod and wedge, that a right-angle unit would be difficult to use for many objects.
Is this 1980's C-11 a classic? It's certainly old fashioned and obsolete by today's standards. They don't make 'em like this anymore.
Not such a bad thing, if you're feeling nostalgic. :grin:


Here's the ol' C-11, with a teensy 3.5" Mak-Cass included for scale...

Attached Thumbnails

  • 685970-Celestron11Qsmall.jpg


#2 Jon Isaacs

Jon Isaacs

    ISS

  • *****
  • Posts: 74927
  • Joined: 16 Jun 2004

Posted 13 November 2005 - 11:49 PM

Clive:

Nice looking scope. Bet it's not so fun to setup.

Have you come up with any theories that explain why this scope might be brighter than a 60mm F15 refractor???

Jon

#3 matt

matt

    Vendor (Scopemania)

  • *****
  • Posts: 10991
  • Joined: 28 Jul 2003

Posted 14 November 2005 - 05:09 AM

The Nexstar looks so cuuuute next to it! Or, more so, it looks like a big eyepiece on a tripod.

#4 Clive Gibbons

Clive Gibbons

    Mostly Harmless

  • *****
  • topic starter
  • Posts: 16724
  • Joined: 26 May 2005

Posted 14 November 2005 - 09:02 AM

Clive:

Nice looking scope. Bet it's not so fun to setup.

Have you come up with any theories that explain why this scope might be brighter than a 60mm F15 refractor???

Jon


I'm still very puzzled about that, Jon.
Perhaps it's just an optical illusion.
A bigger dew cap on the 60mm might help... ;)

#5 Clive Gibbons

Clive Gibbons

    Mostly Harmless

  • *****
  • topic starter
  • Posts: 16724
  • Joined: 26 May 2005

Posted 14 November 2005 - 09:07 AM

The Nexstar looks so cuuuute next to it! Or, more so, it looks like a big eyepiece on a tripod.


Thanks, Matt.
The wee Mak's full aperture is smaller than the C-11's central obstruction.
Sits in it's shadow in more ways than one! :D

#6 davidmcgo

davidmcgo

    Mercury-Atlas

  • *****
  • Posts: 2896
  • Joined: 09 Oct 2004

Posted 14 November 2005 - 09:07 PM

Hi Clive,

The tube was meant to come out of the forks on the old C11 and 14. I had an orange tube, and there were a couple of socket head screws just sticking out of the rear cell that fit into slots in the "saddle plates" on the fork that held the tube when pointed straight up to allow you to insert or reomove the 1/4x20x5/8 socket head screws from the outside of the saddle plates. The heaviest weight is then the fork and drive, and nothing more than 30 pounds.

The first time you try this, do it on the carpet with the tube laying on its side in case the original owner never put the shorter screws into the rear cell, and have someone help the first time or two you have a go at it as lining up the first few times is difficult. With practice it was quite easy. You might check around for a C11/C14 manual from the old days as they illustrated this technique.

The mounting bolts you insert and remove to release the OTA from the saddle plates need to be exactly 5/8" long, and the only place I found those was at www.mcmaster.com. Best of luck!

Dave

#7 Clive Gibbons

Clive Gibbons

    Mostly Harmless

  • *****
  • topic starter
  • Posts: 16724
  • Joined: 26 May 2005

Posted 15 November 2005 - 09:19 AM

Hi Clive,

The tube was meant to come out of the forks on the old C11 and 14. I had an orange tube, and there were a couple of socket head screws just sticking out of the rear cell that fit into slots in the "saddle plates" on the fork that held the tube when pointed straight up to allow you to insert or reomove the 1/4x20x5/8 socket head screws from the outside of the saddle plates. The heaviest weight is then the fork and drive, and nothing more than 30 pounds.

The first time you try this, do it on the carpet with the tube laying on its side in case the original owner never put the shorter screws into the rear cell, and have someone help the first time or two you have a go at it as lining up the first few times is difficult. With practice it was quite easy. You might check around for a C11/C14 manual from the old days as they illustrated this technique.

The mounting bolts you insert and remove to release the OTA from the saddle plates need to be exactly 5/8" long, and the only place I found those was at www.mcmaster.com. Best of luck!

Dave


Thanks for the info, Dave.
Yup, the tube fits onto the forks via 4 cap screws and Celestron recommends that users assemble it that way when setting up.
However, I've always tried to avoid the extra step when possible, so keeping the OTA and forks together does the trick. It's near the limit of what I can heft onto the wedge in one go.
One day, I'll have to admit defeat and do it "by the book"...

#8 davidmcgo

davidmcgo

    Mercury-Atlas

  • *****
  • Posts: 2896
  • Joined: 09 Oct 2004

Posted 15 November 2005 - 10:35 PM

Hi Clive,

I used to do OK putting the scope onto the wedge, it was unhooking the whole mess from the two shoulder bolts on the wedge to dismount that nearly wrecked everything for me. Those things fit into the "keyhole" slots in the drive base to let everything hang while installing the 3 bolts to mount the drive base since the top wasn't slotted the way the C8 wedge and the Meades are.

My present big schmidt is an old C10 from 1965 and that can't remove the tube by any easy means, so I do have a 70 pound single piece to deal with. At least the forks are shorter!

Dave

#9 Clive Gibbons

Clive Gibbons

    Mostly Harmless

  • *****
  • topic starter
  • Posts: 16724
  • Joined: 26 May 2005

Posted 16 November 2005 - 09:14 AM

Hi Clive,

I used to do OK putting the scope onto the wedge, it was unhooking the whole mess from the two shoulder bolts on the wedge to dismount that nearly wrecked everything for me. Those things fit into the "keyhole" slots in the drive base to let everything hang while installing the 3 bolts to mount the drive base since the top wasn't slotted the way the C8 wedge and the Meades are.

My present big schmidt is an old C10 from 1965 and that can't remove the tube by any easy means, so I do have a 70 pound single piece to deal with. At least the forks are shorter!

Dave


You've got it, Dave!
It can be tricky getting the C-11 onto the wedge, but it's sometimes even finickier dismounting it. That's where my wife come in, with a flashlight, to help out.... if she's awake. ;)

Your C10 is a TRUE classic! :bow:

I'd love to look thru one, someday...

Clear skies,

Clive.


CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics