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

Using an 8SE with Barlow and Full Frame Camera

  • Please log in to reply
5 replies to this topic

#1 safinsd

safinsd

    Sputnik

  • -----
  • topic starter
  • Posts: 31
  • Joined: 30 Nov 2018

Posted 14 January 2022 - 10:33 PM

I've been wandering through the Internet for days looking for an answer, no joy. I am taking lunar images with an 8SE using an A7III connected to the rear cell via a t-adapter and t-ring. I want to introduce a TeleVue 2x Barlow into this imaging train.
Two questions:
1. Will adding the Barlow in this case work?
2. If yes, exactly how can I do it and what do I need, other than the Barlow itself?
An image would be greatly appreciated.

#2 Porkkala

Porkkala

    Vostok 1

  • -----
  • Posts: 152
  • Joined: 19 Apr 2020
  • Loc: Finland

Posted 15 January 2022 - 03:16 AM

You need to use the visual back.
Camera: remove the lens, put a camera specific t2 adapter on.
Buy a t2-1.25 " nosepiece, connect that to the camera
Put the visual back into the scope
Put the barlow into the visual back
Put the nose piece into the barlow.

#3 safinsd

safinsd

    Sputnik

  • -----
  • topic starter
  • Posts: 31
  • Joined: 30 Nov 2018

Posted 15 January 2022 - 04:09 AM

Thank you! Do you by any chance know if I can use the Televue 2X this way - will it achieve focus with a DSLR? Also, do you have a recommendation for a good Barlow 2X?
Thanks for your help. 🙂

#4 Borodog

Borodog

    Soyuz

  • *****
  • Posts: 3,681
  • Joined: 26 Oct 2020

Posted 15 January 2022 - 10:48 AM

The A7III is a full frame camera and the 8SE is not coma corrected. You may have noticeable coma, although depending on your presentation scale it may not bother you. Also I'm not sure I would use 1.25" components rather than 2". Depending on the Barlow it may induce chromatic aberration as well; I'm not familiar with the TV 2X.


Edited by Borodog, 16 January 2022 - 09:48 AM.

  • Porkkala likes this

#5 Porkkala

Porkkala

    Vostok 1

  • -----
  • Posts: 152
  • Joined: 19 Apr 2020
  • Loc: Finland

Posted 15 January 2022 - 11:54 AM

I'm sure you will reach focus, an SCT is very adaptable because the main mirror moves. I don't see any reason why you wouldn't reach focus.
But Borodog is right, with a full frame sensor the result may not be what you expect. Only a portion of the frame may be good enough for you.
If you're considering a barlow, you are probably trying to image details rather than the full disk of the moon. Instead of investing in a barlow, consider investing the same amount in a small planetary camera, with a pixel size of maybe 2.4 or 2.9 microns. The image scale with no barlow will be equivalent to what you'll achieve with the Sony + barlow, but the result will probably be better.

#6 safinsd

safinsd

    Sputnik

  • -----
  • topic starter
  • Posts: 31
  • Joined: 30 Nov 2018

Posted 15 January 2022 - 03:16 PM

Thank you. I'm considering both an ASI224MC and a Barlow.


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