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

An Evening with the "Mighty" Celestron C90

  • Please log in to reply
7 replies to this topic

#1 james7ca

james7ca

    Cosmos

  • *****
  • topic starter
  • Posts: 9,482
  • Joined: 21 May 2011
  • Loc: San Diego, CA

Posted 04 August 2020 - 05:46 AM

Okay, don't expect wonders here with just 90mm of aperture on the spotting-scope variety of Celestron's C90 Maksutov-Cassegrain.

 

All of these images where taken on the evening of July 29, 2020 using the C90 and an uncooled ZWO ASI174MM camera with a Celestron 2X Ultima SV barlow (giving an e.f.l. of about 3500mm, f/39, since the barlow was producing significantly more than 2X on this native f/13.9 system). Because of the latter I ended up reducing most of these images to about 75% of the original capture scale. All of this was carried on my similarly mighty Celestron AVX mount (is that too much use of "mighty?").

 

The color images of Jupiter and Saturn were taken using a set of ZWO RGB filters while the remainder are mono images taken with a Baader 610nm long pass filter.

 

Image processing with AutoStakkert!, Registax, PixInsight, and Photoshop CC2019. Image capture done with SharpCap.

 

I started on the gibbous moon and then took a few images of Vega and the Double-Double star in the constellation Lyra to help determine my image scale. Then I went on to Jupiter and Saturn before my session was ended just before 11PM PDT by marine layer clouds.

 

First up, the lunar southern highlands (with Tycho and Clavius) and the northern Mare Imbrium (with Plato, Archimedes, and the Hadley Rille).

Attached Thumbnails

  • Lunar Southern Highlands using C90 with ASI174MM.jpg
  • Mare Imbrium using C90 with ASI174MM.jpg

Edited by james7ca, 04 August 2020 - 07:21 AM.

  • Diego, zjc26138, Sunspot and 18 others like this

#2 james7ca

james7ca

    Cosmos

  • *****
  • topic starter
  • Posts: 9,482
  • Joined: 21 May 2011
  • Loc: San Diego, CA

Posted 04 August 2020 - 05:47 AM

Copernicus is next, followed by Jupiter and Saturn and then Vega (showing diffraction rings) and the Double-Double star Epsilon Lyrae.

Attached Thumbnails

  • Copernicus using C90 with ASI174MM.jpg
  • Jupiter and Io using C90 with ASI174MM.jpg
  • Saturn and Five Moons using C90 with ASI174MM.jpg
  • Vega using C90 with ASI174MM.jpg
  • Epsilon Lyrae using C90 with ASI174MM.jpg

Edited by james7ca, 04 August 2020 - 05:48 AM.

  • Diego, zjc26138, Sunspot and 24 others like this

#3 james7ca

james7ca

    Cosmos

  • *****
  • topic starter
  • Posts: 9,482
  • Joined: 21 May 2011
  • Loc: San Diego, CA

Posted 04 August 2020 - 07:14 AM

And, an image of the C90 itself. I also used a LONG dew shield that was made from a cardboard carton that previously held 12-cans of Dr. Pepper, but that's not a particularly photogenic addition and I need to make a better shield from some neoprene foam sheets that I have for just that purpose.

Attached Thumbnails

  • Celestron C90 and ZWO ASI174MM.jpg

  • zjc26138, Sunspot, Jaimo! and 4 others like this

#4 JMP

JMP

    Apollo

  • *****
  • Posts: 1,027
  • Joined: 31 Oct 2005

Posted 04 August 2020 - 08:32 PM

Nice work, James!



#5 RickD_99

RickD_99

    Explorer 1

  • -----
  • Posts: 70
  • Joined: 02 May 2020
  • Loc: Central Alabama USA

Posted 04 August 2020 - 10:40 PM

Beautiful images James!



#6 james7ca

james7ca

    Cosmos

  • *****
  • topic starter
  • Posts: 9,482
  • Joined: 21 May 2011
  • Loc: San Diego, CA

Posted 05 August 2020 - 01:10 AM

JMP and Rick and all the other likes, thanks for the notice.

 

I just got an adapter that converts the non-standard threads on the rear of the C90 to the more common 2" SCT thread and that will allow me to use the same types of setups that I use on my C6 and EdgeHD. That could improve the results and will certainly allow me to image closer to the critical sampling of the C90 (rather than the oversampled results I got with the Celestron 2X barlow). This isn't the first time that I've used the C90 for lunar imaging and I think I've done better in the past (see here and here), so this is yet another example of how seeing matters most of all even with a scope as small as the C90.



#7 DMach

DMach

    Surveyor 1

  • -----
  • Posts: 1,650
  • Joined: 21 Nov 2017
  • Loc: The most light-polluted country in the world :(

Posted 06 August 2020 - 09:56 AM

Might indeed! Nice images there.  :)



#8 james7ca

james7ca

    Cosmos

  • *****
  • topic starter
  • Posts: 9,482
  • Joined: 21 May 2011
  • Loc: San Diego, CA

Posted 06 August 2020 - 10:49 AM

Might indeed! Nice images there.  smile.gif

Thanks.

 

I've been very happy with my C90, the focuser is smooth and precise and the scope is easy to handle and very portable. It can't cover a full APS-C format with good sharpness but with a smaller format camera it is very well suited for taking quick mosaics of the full disk of the moon.


Edited by james7ca, 06 August 2020 - 01:20 PM.



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