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

Suggestions for autoguiding with a less than optimum setup/Nextar Evo 8HD

  • Please log in to reply
5 replies to this topic

#1 qprmeteor

qprmeteor

    Sputnik

  • -----
  • topic starter
  • Posts: 30
  • Joined: 30 Sep 2007
  • Loc: Waterford, Ireland

Posted 22 October 2020 - 04:38 PM

Hi all.

 

I have a Nexstar Evolution 8HD scope, bought a few months back. Been playing around with simple astrophotography with it over the last few months, mostly planetary, and I've gotten the astophotography bug. Have been using a Canon EOS 250D, with good results.

 

Upgrading to a proper equatorial mount is not an option, but I do have the Celestron wedge for the scope - not ideal, but will have to do under the circumstance.

I'm looking at/wondering what my best options for autoguiding would be, as I'd not like to be constained to max 30 sec for subs. The plethora of options & advice are confusing - is it possible to use a guide scope and camera to autoguide with this scope, given its focal length (such as the Orion StarShoot AutoGuider and 60mm guide scope combo) or is the only option to use an off axis guider (such as the Celestron Deluxe) with a mono camera for autoguiding? My worry is the small FOV with an OAG, and the lack of sensitivity in such a small field would make it hard to find guide stars. Also, I read that you can't use the focal reducer for the Edge 8HD with the Celestron Deluxe OAG due to lack of back focus spacing...

 

It's not the most optimum set up, but looking for something that would maximise what I can do, without breaking the bank (i.e. as cheap as possible!!).

Cheers.

Brian


Edited by qprmeteor, 22 October 2020 - 04:40 PM.


#2 rgsalinger

rgsalinger

    Fly Me to the Moon

  • *****
  • Moderators
  • Posts: 7,363
  • Joined: 19 Feb 2007
  • Loc: Carlsbad Ca

Posted 22 October 2020 - 04:54 PM

I think that you can try to use a guidescope and will get decent results if you lock down the mirror as best you can. However, there's are tons of OAG's that do not take up so much back focus as the Celestron does which would suit your purpose. If you go the OAG route I would not use an 8 bit camera like the SSAG, you'll need something more sensitive and with a larger field of view. Again, some people do use guide scopes and they seem to be happy with what they see. It's as much about how picky you are as anything else.

Rgrds-Ross



#3 qprmeteor

qprmeteor

    Sputnik

  • -----
  • topic starter
  • Posts: 30
  • Joined: 30 Sep 2007
  • Loc: Waterford, Ireland

Posted 23 October 2020 - 01:45 AM

Many thanks Ross - any suggestions for a suitable OAG and camera? The options are a bit bewildering - certainly don't want to make a poor choice!



#4 Cfreerksen

Cfreerksen

    Apollo

  • *****
  • Posts: 1,186
  • Joined: 18 Aug 2018
  • Loc: Tooele, Ut

Posted 23 October 2020 - 04:09 PM

You can spend money on an OAG and a camera. You are going to need those anyway with your scope. If you own the wedge, use it. I can tell you from experience that you are not really going to get too far from there and will be wanting a gem mount soon. I say this from experience. The wedge will seriously restrict your imaging choices due to not being able to slew to certain areas of the sky unless you use a diagonal. It only took 1 time for my cameras usb plug to strike the mount and nearly destroy my $900 camera and I knew it was new mount time.

Just be careful and it is possible to get a Nexstar mount to pulse guide. Even though you may still be tossing a fair amount of your subs over 90 seconds. You can get good results with HyperStar with it’s much more forgiving focal length. But that is a fairly pricey venture too and OAG guiding is not possible.

Chris

Edited by Cfreerksen, 23 October 2020 - 04:12 PM.


#5 Stelios

Stelios

    Voyager 1

  • *****
  • Moderators
  • Posts: 10,449
  • Joined: 04 Oct 2003
  • Loc: West Hills, CA

Posted 23 October 2020 - 05:35 PM

As cheap as possible: Get the ZWO OAG ($128) and the ZWO ASI290MM-mini camera ($299). 

 

You don't need the Celestron Deluxe OAG for an Edge 800 with reducer. And you won't have any back focus issues. 


  • qprmeteor likes this

#6 qprmeteor

qprmeteor

    Sputnik

  • -----
  • topic starter
  • Posts: 30
  • Joined: 30 Sep 2007
  • Loc: Waterford, Ireland

Posted 24 October 2020 - 12:25 PM

Many thanks all for the responses. I've decided that the Edge 8HD is not worth going after for deep sky stuff - it just seems too much effort, particularly as I'm new to astrophotography and don't want my interest killed too early by fighting with setups!

 

I've taken advice from elsewhere - I have an old Nexstar 80GT lying around, and I'll experiment with that for the next while. While optically it's obviously sub-par, it'll be good enough to get familar with the basics of deep sky imaging. I've ordered the ZWO Mini Finder-Guider & ASI120MM-Mini for guiding - they seem ideal for such an instrument.

 

What I image won't be perfect by any means - but hopefully it'll be a lot more fun and easier to learn.

(The Edge 8HD is still going to be my go-to instrument for planetary and lunar imaging, though!!)

 

Thanks again!

 

Brian


  • Cfreerksen likes this


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