Return to the Cloudy Nights Telescope Reviews home pageAstronomics discounts for Cloudy Nights members
· Get a Cloudy Nights T-Shirt · Submit a Review / Article

Click here if you are having trouble logging into the forums

Privacy Policy | Please read our Terms of Service | Signup and Troubleshooting FAQ | Problems? PM a Red or a Green Gu… uh, User

Equipment Discussions >> Cats & Casses

Pages: 1 | 2 | 3 | (show all)
Greg Boynton
member


Reged: 05/29/09

Re: old C8 vs new C8 new [Re: Erik Bakker]
      #5694393 - 02/22/13 10:27 AM

I agree, I'll take the better figure over better coatings any day.

Post Extras: Print Post   Remind Me!   Notify Moderator  
magnus
professor emeritus


Reged: 03/17/04

Loc: Visby, Sweden
Re: old C8 vs new C8 new [Re: Greg Boynton]
      #5695038 - 02/22/13 03:54 PM

Thanks Greg & Erik for your opinions. I fully agree with you. -Rather good optics & less excellent coatings than the opposite.
In my initial post, I wrote as far as I can evaluate from startesting & observing Jupiter (well also Mars & Saturn)I find the optics not perfect but good for a massproduced optics. Maybe not saying all that much!?But: Comparing my C8+f/6.3 f/r vs my OOUK 8"f/6 Newt. with zygodocument stating something like strehl 98% and 1/7 wave and 44mm secondary,Hi-Lux coatings the Newt. shows Jupiter as just a bit brighter & whiter, with low contrast details just a tiny bit easier to detect in excellent seeing. Also the "e" & "f" stars in the Trapezium are defenitely easier to detect in the Newt.(Hi-Lux?)In "normal" conditions any differences are hard to notice.
Still my C8 get most use as it is so ergonomic and short, except when I use my Gemini alt-az mount, than the 8" Newt is my obvious choice. In case anyone is intressted

/Magnus 57N.


Post Extras: Print Post   Remind Me!   Notify Moderator  
WillCarney
Pooh-Bah
*****

Reged: 10/08/09

Loc: Bloomington, ILL
Re: old C8 vs new C8 new [Re: magnus]
      #5695111 - 02/22/13 04:32 PM

Well I have a black C-8 from the early 80's. It's great and recently I had it back to back with the clubs C-11 HD. Well would you know it. My C-8 out performed the C-11 HD visually with the same eyepieces. I actually got dimmer and brighter stars with my C-8. Hard to believe but I repeated it on several occasions. William

Post Extras: Print Post   Remind Me!   Notify Moderator  
rflinn68
Carpal Tunnel


Reged: 03/09/12

Loc: Arkansas
Re: old C8 vs new C8 new [Re: WillCarney]
      #5695183 - 02/22/13 05:09 PM

I have a mid-90's black tube C8 and I wouldnt trade it for anything other than an EdgeHD (8" vs 8"). Mine compared better than a friends similar model C8 and every bit as good as a brand new dark orange tube 8SE. I might even sell my 10" Meade SCT someday soon and buy the EdgeHD and keep my black tube C8. I like it that much! But I like my Meade too! Maybe I'll keep them both and just buy the EdgeHD! Everbody needs two 8" SCT's and a 10" SCT. Right?

Post Extras: Print Post   Remind Me!   Notify Moderator  
magnus
professor emeritus


Reged: 03/17/04

Loc: Visby, Sweden
Re: old C8 vs new C8 new [Re: rflinn68]
      #5695275 - 02/22/13 05:50 PM

Congrats Will & Richard to excellent black C8:s. Seems like I should be careful not to be blinded by XLT coating ads and truly have a second thought before I rush and buy a brand new C8 XLT. Well even if I did my beutiful 1973 orange Pacific C8 with it`s original thrunk will never be up for sale.-Just as my beutiful second hand Intes MK66!
/Magnus 57N.
PS Will, what was wrong with the C11. Something must be wrong if 8" outperforms 11",even if I have no doubts your 8" is very good indeed!!

Edited by magnus (02/22/13 05:57 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
watcher
Carpal Tunnel
*****

Reged: 11/21/07

Loc: St. Louis, MO
Re: old C8 vs new C8 new [Re: magnus]
      #5695320 - 02/22/13 06:12 PM

I think, if this is going to be your only scope, you might consider an Edge 8 CPC. Passive cooling would be beneficial in your climate. The fork mounts are more comfortable to view with, and I haven't seen a single report of anything but great optical quality in any Edge scope. besides that, you will get the best coatings available. I just think if your only going to have one scope to do it all, it's worth spending a little extra.

Post Extras: Print Post   Remind Me!   Notify Moderator  
rflinn68
Carpal Tunnel


Reged: 03/09/12

Loc: Arkansas
Re: old C8 vs new C8 new [Re: watcher]
      #5695350 - 02/22/13 06:29 PM

Post Deleted by rflinn68

Post Extras: Print Post   Remind Me!   Notify Moderator  
Julio
sage
*****

Reged: 01/18/07

Loc: Pembroke Pines ,FL
Re: old C8 vs new C8 new [Re: rflinn68]
      #5695451 - 02/22/13 07:31 PM

Optical figure trumps everything, some have tested their C8-C14s and have found that they surpass 1/8 PV. While not common, such a SCT of mass production is in the excellent to superb category and an outstanding value and worthy of reacoating.

Post Extras: Print Post   Remind Me!   Notify Moderator  
mike174
scholastic sledgehammer


Reged: 01/04/05

Loc: Central, NJ
Re: old C8 vs new C8 new [Re: Erik Bakker]
      #5695552 - 02/22/13 08:14 PM

Quote:

Magnus,

If your C8 has very good optics, that quality will have a profound impact on high power detail and contrast. No modern coating can make up for that. Only if the modern sample has similar high quality optics, than the coatings will add a little extra. Make sure you test any new C8 side-side with your old C8 at identical magnifications with identical eyepieces and diagonals. The coatings will do good on very low power views. As soon as you go to 150x and up, the quality of the optics will reveal themselves. Not only in the level of detail, but also in the steadiness of observable detail. Like the better scope has better seeing, while in fact it has better optics under similar seeing.




I noticed that when viewing the moon through a Mewlon 250 a few towns away under typical NJ skies. The sharpness of the optics was easily seen through the seeing. My 2007/2008 C11 seems to loose sharpness when I go eyepieces smaller than 20mm.

My Orange C8 seems to be almost the same on either side of focus unlike my C11.

MIke


Post Extras: Print Post   Remind Me!   Notify Moderator  
Bill Barlow
Carpal Tunnel
*****

Reged: 12/03/07

Loc: Overland Park KS
Re: old C8 vs new C8 new [Re: WillCarney]
      #5695564 - 02/22/13 08:22 PM

Seems hard to believe that your C8 can show dimmer and brighter stars than a C11. Did you do the side by side using similar magnifications or the same focal length eyepiece in each? This would make the C11 use a higher magnification given it's longer focal length. The much higher light grasp of the C11 should be noticeable versus the C8 I would think.

Bill


Post Extras: Print Post   Remind Me!   Notify Moderator  
Brian Risley
Carpal Tunnel
*****

Reged: 09/04/06

Loc: SW Florida
Re: old C8 vs new C8 new [Re: rflinn68]
      #5695841 - 02/22/13 11:06 PM

Just 2 C-8's? I have 3 and also the club's CPC-800 along with my Meade 10!
Brian

Quote:

I have a mid-90's black tube C8 and I wouldnt trade it for anything other than an EdgeHD (8" vs 8"). Mine compared better than a friends similar model C8 and every bit as good as a brand new dark orange tube 8SE. I might even sell my 10" Meade SCT someday soon and buy the EdgeHD and keep my black tube C8. I like it that much! But I like my Meade too! Maybe I'll keep them both and just buy the EdgeHD! Everbody needs two 8" SCT's and a 10" SCT. Right?




Post Extras: Print Post   Remind Me!   Notify Moderator  
rflinn68
Carpal Tunnel


Reged: 03/09/12

Loc: Arkansas
Re: old C8 vs new C8 new [Re: Brian Risley]
      #5695910 - 02/23/13 12:06 AM

Quote:

Just 2 C-8's? I have 3 and also the club's CPC-800 along with my Meade 10!
Brian

Quote:

I have a mid-90's black tube C8 and I wouldnt trade it for anything other than an EdgeHD (8" vs 8"). Mine compared better than a friends similar model C8 and every bit as good as a brand new dark orange tube 8SE. I might even sell my 10" Meade SCT someday soon and buy the EdgeHD and keep my black tube C8. I like it that much! But I like my Meade too! Maybe I'll keep them both and just buy the EdgeHD! Everbody needs two 8" SCT's and a 10" SCT. Right?







The more the merrier, right?


Post Extras: Print Post   Remind Me!   Notify Moderator  
jrbarnett
Eyepiece Hooligan
*****

Reged: 02/28/06

Loc: Petaluma, CA
Re: old C8 vs new C8 new [Re: Julio]
      #5697493 - 02/23/13 10:38 PM

Better still, you can get used, recent C8s for $350. They depreciate a lot.

- Jim


Post Extras: Print Post   Remind Me!   Notify Moderator  
greedyshark
professor emeritus
*****

Reged: 10/31/05

Loc: 3rd Rock
Re: old C8 vs new C8 new [Re: bob midiri]
      #5698880 - 02/24/13 08:26 PM

Quote:

I recommend that you find some one local that has the Newer C8 that you are thinking of purchasing and see for yourself how your old C8 compares in a one to one showdown, directly with that scope using the same eyepiece and same diagonal. It might not be as big a jump as you might be anticipating...Bob




I agree with Bob 100%. I own an early '80s orange tube...outstanding optics! I will pass this one to my boy.

Charles


Post Extras: Print Post   Remind Me!   Notify Moderator  
rfic1
sage
*****

Reged: 10/25/05

Re: old C8 vs new C8 new [Re: greedyshark]
      #5698894 - 02/24/13 08:41 PM

I owned a 1976 Celestron Pacific C8 that I felt had outstanding optics. It almost always provided better planetary views than multiple 5" APO's I owned. I purchased a TEC 200MC and that is the reason why I parted with it. Yes the TEC is better, but at 7 times the cost. Plus it is not as portable and requires a substantial mount. I still miss that scope. One that I wish I never let go.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Greg Boynton
member


Reged: 05/29/09

Re: old C8 vs new C8 new [Re: rfic1]
      #5700407 - 02/25/13 06:57 PM

I also had an orange 70's C8 that had really sharp views. I didn't appreciate how good it was though and sold it in a fit of aperture fever. After looking through a whole bunch of SCT's since and getting educated, I realized that I screwed up. I do agree that the newer scopes seem to be more consistently good, but I wouldn't count on any given sample as being an upgrade.

I guess the lesson is: Never sell a scope which gives great views unless you are dang sure the replacement is actually better for you.


Post Extras: Print Post   Remind Me!   Notify Moderator  
orion61

*****

Reged: 10/20/07

Loc: Birthplace James T Kirk
Re: old C8 vs new C8 new [Re: Greg Boynton]
      #5700467 - 02/25/13 07:41 PM

I have a C8 that was made for former Celestron VP of sales Leo Henzl, there are hand written notes on the back of the mirror in blue marker and it describes the extra figuring process and his name.
With my F 6.3 FF/FR I cant imagine anything sharper! I have owned C8's since the 70's this one is sure a keeper,
Even at the price I got it for.
I am debating sending the mirrors in for enhanced coatings.
The stock ones look good with no pin holes..
I just don't know what to do...


Post Extras: Print Post   Remind Me!   Notify Moderator  
bob midiri
Carpal Tunnel
*****

Reged: 06/17/04

Loc: pa 19320
Re: old C8 vs new C8 new [Re: orion61]
      #5700487 - 02/25/13 07:59 PM

Larry why mess with perfection!!! Enjoy that scope, how much can really be gained by the coatings. use a 99% reflective diagonal to increase a little light going to your eyepiece...if you don't already!! Bob

Post Extras: Print Post   Remind Me!   Notify Moderator  
magnus
professor emeritus


Reged: 03/17/04

Loc: Visby, Sweden
Re: old C8 vs new C8 new [Re: bob midiri]
      #5704341 - 02/27/13 09:46 PM

This evening, before moonrise,I used my friend`s C8 XLT to see how it performes vs my old orange C8 Pacific -73. My friend Roger (sunrutas) is also a CN member but he is 100% imaginer, mostly planets. Now and than he visits solar system imagening forum to show his amazing Jupiter/Saturn pictures taken with his C8XLT & C925XLT.

Anyway this evening I got the chance to have a look tru`his C8XLT from his balcony, were he has a very solid pier & an CG-5 mount on top of it. I also often observe from my balcony so the conditions were very similar. I had taken my eypieces, diagonal & focalreducer with me to use on Rogers scope.

I had a look at Jupiter, Rigel, Alnitak, Trapezium, Sigma Orionis, gamma Leo. All in all I could not notice any distinct difference. Jupiter looked pretty much the same as in my old C8; details and contrast very much the same. Possibly J. was a bit whiter & brighter in XLT but I am not certain. No e or f star in Trapizium but not often I see those in my C8 either. (M42 don`t get high over horizion up here)More easy in my 8" f/6 OOUK Newt. But the four "original" Trap. stars were defenitely more distinct & pinpont in my C8. Strange! The C component in Sigma Ori. was harder to see in the C8XLT than in my C8.Even more strange!! I could not notice any difference when observing Rigel, Alnitak & gamma Leo.

A quick startest gave pretty much the same result in both scopes; not perfect but pretty good.

I am very surprised & glad how extremely well my classic C8 hold up against a brand new XLT. Tom Johnsson had certainly done his homework before starting massproducing the C8 1970!

A test C8 vs C8 XLT on a dark place with no moon might have tipped the advantage over to the C8XLT but I very much doubt it, not in a
dramatical way, anyway.

I will keep my beutiful 40 (!!) year old orange C8 Pacific & take good care of it & use it as much as I can.

Best Regards,
Magnus 57N.

PS Seeing was: ca. 5/10 P.


Post Extras: Print Post   Remind Me!   Notify Moderator  
bob midiri
Carpal Tunnel
*****

Reged: 06/17/04

Loc: pa 19320
Re: old C8 vs new C8 new [Re: magnus]
      #5704380 - 02/27/13 10:09 PM

Nice report Magnus, Im glad you saw for yourself... Bob

Post Extras: Print Post   Remind Me!   Notify Moderator  
Pages: 1 | 2 | 3 | (show all)


Extra information
14 registered and 17 anonymous users are browsing this forum.

Moderator:  Starman27, kkokkolis 

Print Thread

Forum Permissions
      You cannot start new topics
      You cannot reply to topics
      HTML is disabled
      UBBCode is enabled


Thread views: 3296

Jump to

CN Forums Home


Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics