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

Orion ST 80 diagonal question

  • Please log in to reply
8 replies to this topic

#1 Defenderslideguitar

Defenderslideguitar

    Surveyor 1

  • *****
  • topic starter
  • Posts: 1613
  • Joined: 05 Oct 2016
  • Loc: Connecticut

Posted 14 August 2019 - 06:30 PM

Hi   so several months ago I bought an older Orion ST 80    seems good but  I am just now starting to use it a bit and I cannot figure out the funny ball shaped looking diagonal.....it does not seem to be right

.I can pop in  a celestron diagonal  I guess

I am contemplating the  2 inch focuser upgrade down the road    but for now   Can anyone tell me what this is?

 

Could this possibly be the correct original diagonal?

 

thanks

 

 

Attached Thumbnails

  • orionst80diagIMG_3916.jpg
  • Orionst80diagonalsIMG_3922.jpg
  • orionstdiagonalIMG_3921.jpg


#2 tony_spina

tony_spina

    Mercury-Atlas

  • *****
  • Posts: 2555
  • Joined: 14 Jun 2004
  • Loc: So. Cal.

Posted 14 August 2019 - 06:32 PM

That is not the original diagonal.   That is a celestron correct image mirror diagonal included in their lower end scopes


  • Jon Isaacs, deepwoods1, waso29 and 3 others like this

#3 agmoonsolns

agmoonsolns

    Apollo

  • *****
  • Posts: 1386
  • Joined: 17 Sep 2018
  • Loc: Washington

Posted 14 August 2019 - 06:36 PM

The tend to be garbage too. The last one I had, I just threw away. It was so bad, it wasn't even good enough to give away. Put a better diagonal in and you should be getting much better images.


  • waso29, BFaucett and Defenderslideguitar like this

#4 drd715

drd715

    Explorer 1

  • -----
  • Posts: 72
  • Joined: 07 Jan 2015
  • Loc: Fort Lauderdale

Posted 14 August 2019 - 07:08 PM

While that correct image diagonal may be of poor quality there are quality prizm diagonals both 45 degree and 90 degree versions available. They are used for terrestrial views and aiming finders that are intuitive in moving the main scope into position. Right is right, up is up. Traditional diagonals will flip or reverse your image depending upon the type of scope they are used in. A 90 degree correct image finder works well on a push to aim DOB for example

Sent from my SM-N950U using Tapatalk
  • jcj380 and Defenderslideguitar like this

#5 Defenderslideguitar

Defenderslideguitar

    Surveyor 1

  • *****
  • topic starter
  • Posts: 1613
  • Joined: 05 Oct 2016
  • Loc: Connecticut

Posted 14 August 2019 - 07:51 PM

Thanks to all

 

I have another diagonal to try in it for sweeping and if the ST80 rides aboard another scope someday as a guidescope  I can do the correct image thing as well but not with this round ball

Im not using this     ball like thing    

 

Thanks    

Barry



#6 Redbetter

Redbetter

    Cosmos

  • *****
  • Posts: 7708
  • Joined: 16 Feb 2016
  • Loc: Central Valley, CA

Posted 14 August 2019 - 07:52 PM

That is not the original diagonal.   That is a celestron correct image mirror diagonal included in their lower end scopes

Correct, it is the Celestron RACI.  There might not have been an original diagonal, depends on whether the ST80 was originally purchased as an OTA or one of the packages. 



#7 jcj380

jcj380

    Apollo

  • *****
  • Posts: 1460
  • Joined: 08 Jul 2014
  • Loc: 42N 88W

Posted 15 August 2019 - 07:59 AM

While that correct image diagonal may be of poor quality there are quality prizm diagonals both 45 degree and 90 degree versions available. They are used for terrestrial views and aiming finders that are intuitive in moving the main scope into position. Right is right, up is up. Traditional diagonals will flip or reverse your image depending upon the type of scope they are used in. A 90 degree correct image finder works well on a push to aim DOB for example

I went with a RACI diagonal for my push-to ST120 and ST80 clone and I doubt I'll ever go back to a flipped diagonal.  Left is left and up is up makes things a boatload easier IMO.  Plus I don't have to flip any lunar maps.  YMMV.



#8 Binojunky

Binojunky

    Fly Me to the Moon

  • *****
  • Posts: 5511
  • Joined: 25 Dec 2010

Posted 16 August 2019 - 01:28 PM

I think they package the same diagonal with the Meade Adventure 80 which is a ST80,I could be mistaken?,never even tried mine, just threw it into the box and use a low cost prism diagonal that works just fine,D



#9 Redbetter

Redbetter

    Cosmos

  • *****
  • Posts: 7708
  • Joined: 16 Feb 2016
  • Loc: Central Valley, CA

Posted 16 August 2019 - 02:35 PM

I think they package the same diagonal with the Meade Adventure 80 which is a ST80,I could be mistaken?,never even tried mine, just threw it into the box and use a low cost prism diagonal that works just fine,D

 

The housing is somewhat differently shaped and the nosepieces are somewhat different.  However, they use much of the same internal form, differing in the internal screw pattern for holding it together.  The prisms appear to be the same (without actually removing them.)  They both have what appears to be the same small aperture angular piece covering the prism just below the eyepiece holder. 

 

I haven't measured the actual apertures of these two RACI's, but they appear to be somewhat less than that of the #PD90 GSO RACI (which is identical to a much older RACI that came with an 80mm finder.)  The prisms are likely the same size, but the larger GSO aperture is all the way to the angular edge of the prism.  The GSO RACI has a metal eyepiece holder and weighs 1.3 oz more (3.5 oz vs. 2.2 for the Celestron.)




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