26 replies to this topic

[konrad]

Seems like the Classic scope bug has hit me , thank God is not in the same league as AP at this stage as being semi retired it could be dangerous , anyway I got a C5 spotting scope not sure of the year but had the .965 pack on and on the diagonal box it states 1986

Came with 2 eyepieces a 12mm celestron orthos and a 20mm only marked as R20 (does not seem good quality) I cannibalized a mead camera T adapter to make a 1.25 visual pack , works great.

Put some 140mm rings on and now on a modern tripod.

Now my question will a Hybrid .965 to 1.25 diagonal work the same (I have ordered one)

Attached Thumbnails

• 

[konrad]

some photos of the serial number and  'special coating' which I believe was done a bit later?

Attached Thumbnails

• 
• 

[rogeriomagellan]

The picture posted reminded of the Leonard Nimoy Celestron pic.

 

[Terra Nova]

I use a quality 0.965 to 1.25 inch Japanese prism star diagonal with my classic forked orange tube C5 and it works fine.

[konrad]

Thanks Terra I hope the one I get is OK in South Africa its a lot harder to find Classic stuff , the one I am getting is not a prism just a mirror one

[konrad]

I must also add that the corrective lens looked like milk should of taken a picture it was unbelievable that anyone could see , but it had a few paper spacers that were half eaten so never bothered to replace them  managed to collimate  it so not sure why the paper spacers, perhaps to protect the corrective lens from scratching ?

[Terra Nova]

Hybrid prismatic star diagonals are about impossible to find anymore. Even on the used market. My C5 came as a complete kit and it had a very good 0.965" Celestron prism star diagonal and several quality 0.965" Celestron kelner and ortho eyepieces. That work quite well also. Another possibility is a 0.965" to 1.25" adapter (Fireball makes a nice one) and a 1.25" prism. You don't want to increase the distance between the eyepiece and the lens system tho as it introduces spherical aberation. A Zeiss T2 prism star diagonal and a T-thread adapter is a third alternative.

Edited by terraclarke, 01 December 2016 - 01:50 PM.

[Augustus]

Hybrid prismatic star diagonals are about impossible to find anymore. 

GSO makes one.

 

http://agenaastro.co...m-diagonal.html

Edited by Augustus, 01 December 2016 - 01:56 PM.

[Terra Nova]

That's an erect image diagonal. Has two prisms glued together inside of it. If you look at a bright object against a dark background you seeman illuminated beam (the seam beterrn the prisms) running across the field. Fine for terrestrial or full field lunar landscape viewing but not great for general astronomical viewing.

[davidmcgo]

The Orange Tube C5 can be used with a 1.25" visual back or even a 2" SCT diagonal if you unscrew the 0.965" back.  Threads on the back are same as a C8.  It won't really cover a 2" eyepiece without vignetting, but you certainly aren't limited to the hybrid diagonals or 0.965" to 1.25" expanding adapters.

 

Dave

[Geo.]

I've converted a couple of the .965" VBs by boring them to 1.25" on the lathe. Kind'a nice as I could keep the fit closer than the stock 1.25" VB. Generally, the contemporary run of the mill 1.25" Plossl is a better eyepiece than a Vixen .965" Kellner and waaaay better than a Ramsden.

 

I think Special Coatings on the corrector and the plastic secondary cell are post '76 vintage.

[konrad]

Thanks everyone I did try the 1.25 visual from my Bosma and the 90 Mak but they did not fit. I did make one from a Meade camera T piece so will just shorten it a bit I think it's a bit too long at present

[konrad]

I've converted a couple of the .965" VBs by boring them to 1.25" on the lathe. Kind'a nice as I could keep the fit closer than the stock 1.25" VB. Generally, the contemporary run of the mill 1.25" Plossl is a better eyepiece than a Vixen .965" Kellner and waaaay better than a Ramsden.

 

I think Special Coatings on the corrector and the plastic secondary cell are post '76 vintage.

I think its from 1986 well that's the date on the .965 diagonal box  , which is actually quite good. The orthos 12mm eyepiece gives quite nice view but the other marked as R20  Ramsden? is quite poor, I have a few other .965 eyepieces from my tasco's but all give a very narrow FOV 

I have also thought of boring the existing VB but then I will never be able to use the .965 eyepieces and I think one will loose the end thread ,so don't want to mess the original too much.

Edited by konrad, 02 December 2016 - 10:15 AM.

[Terra Nova]

The Orange Tube C5 can be used with a 1.25" visual back or even a 2" SCT diagonal if you unscrew the 0.965" back.  Threads on the back are same as a C8.  It won't really cover a 2" eyepiece without vignetting, but you certainly aren't limited to the hybrid diagonals or 0.965" to 1.25" expanding adapters.

 

Dave

 

The threads on modern/contemporary 1.25" SCT visual backs work up to a point on the older orange C5s but the threads are slightly different and won't go on much beyond a couple of turns. I guess the 1.25" v.b. on the older orange C8 has the exact same threat count and pitch as the 0.965" v.b. on the orange C5 making them perfectly interchangeable.

[grif 678]

Parks makes a good quality hybrid .965 to 1.25 diagonal for around $50, I had one on my orange tube C-90, which I eventually sold, and hated it ever since.

[Joe Cepleur]

Would this adapter for the old style C90 work? I'd not be surprised, given that your C5 also came with 0.965" accessories. I just bought one for my C90, and have been meaning to write a thread about it. Inserting a 0.965" diagonal into the C90's baffle tube results in a flawed image, because the diagonal fits loosely there; it sits off center and slightly askew, essentially putting the telescope out of collimation. This adapter squares the optical train perfectly to threads machined onto the telescope at the factory for this purpose, while fitting 1.25" accessories natively. Best $30 item ever! 

[Michael Covington]

I've had a C5 since 1980.  I ordered it with a 1.25-inch visual back (for a Celestron 8) and it worked fine with 1.25-inch accessories.  A current Celestron 1.25-inch visual back should work fine.

[photiost]

My C5 also has the 1.25" visual back.

 

.

 

Attached Thumbnails

• 

[apfever]

The early orange tube C5 and C8 have the same technical thread specs as the later ones. The difference is a slightly larger threading on the early ones. It's like the early ones were on the large side of the spec limits and the later ones were on the smaller end of the specs.  Typical progression with things: make them smaller, cheaper, cheesier, and thinner as time goes on.  Give me a simple square block of ice cream in a thin square wax paper container that is often just opened on the end instead of the top, and USED to be 1/2 gallon. Now 1.46723 quarts or what ever.

 

Try to measure the early or later threads on the orange tubes and they default to the same specs. This is why the larger early female threads are sloppy on a later model, and the smaller later female threads have a hard time on the larger early male OTA threads.  They are the same spec threads. This has been beat before, and confirmed. 

[davidmcgo]

The early 1980s version I had worked fine with the current Taiwan made Celestron 1.25" visual back.

 

Dave

[Geo.]

Pretty sure Celestron phased out the orange tube C5 before 1984. Agree with apfever on the VBs. My tricolor C8 and C5 both accept the later VB. By the late '70s there wasn't much difference in the OEM cost of 1.25 and .965" Kellners.

[Terra Nova]

I will have to try my modern 1.25" VB (Meade SCT) again on my old orange tube C5. I only tried it once but it started to misthread after two turns. Never tried it again as I have a very good hybrid prism diagonal.

Edited by terraclarke, 03 December 2016 - 11:07 PM.

[Bomber Bob]

JD loves the white tube C5 spotter.  He got to see the Moon last night.  Besides the original PL25, I gave him two old Meade MAs - 12mm & 9mm.  He's using a camera tripod, but I'll give him my VG2 when I upgrade.  Lucky pup!  He's about 25 miles NW of The Swamp, and didn't get cloud cover as early as me.  Beginner's Luck strikes again!

[konrad]

Thanks again for all the great suggestions I have not had many chances to try it out but did get one morning and one evening to see. I was rather disappointed  with the scope  splitting stars was about the same as my 10 TE, M42 resolved 4 stars but this is more a planetary scope so early in the morning had a look a Jupiter was ok about the same as my 90 Mak but way bellow the 150 Bosma , now I did not look with both at the same time so perhaps seeing was not good , but I struggled to just see the 2 bands ! Perhaps the obstruction is quite large on this scope? Star test is perfect  

[CHASLX200]

Pretty sure Celestron phased out the orange tube C5 before 1984. Agree with apfever on the VBs. My tricolor C8 and C5 both accept the later VB. By the late '70s there wasn't much difference in the OEM cost of 1.25 and .965" Kellners.

Seems around 1982 was about the end of the C5 orang tubes.  I think they made a black tube fork mounted C5 for a short time.  Then they stopped making the C5 for a few years.