Thread: 12
View Single Post
  #4  
Old 22-12-2020, 10:07 AM
Outcast's Avatar
Outcast (Carlton)
Always gonna be a NOOB...

Outcast is offline
 
Join Date: Oct 2008
Location: Cairns, Qld
Posts: 1,289
Quote:
Originally Posted by mswhin63 View Post
I am not sure, maybe someone else can confirm this but the scope appears to be out of collimation.
What makes you say that?

The image is similar to my own early efforts through an 8"SCT on Orion Nebula with a similarly small sensor. A great effort within the limitations the rig presents...

Stars tend to be a bit blobby & at 10sec exposure time on an Alt/Az mount, a little star stretching begins to occur as you push the limits of tracking... plus, I think he's using a generic 0.5x focal reducer which, from my experience aren't particularly well corrected.

What indicators make you think it might be out of collimation, am I missing something?

To the OP:

A great start to your imaging journey, it's exactly where I started.. be careful, it's a slippery slope to great expense... I'm only a sporadic imager, still get way too much kick out of visual observing but, have delved in somewhat deeper since producing my early Orion images... still not up to par with the standards of many others on here...

Are you using a bhatinov mask to achieve focus or are you attempting to do it by eye? A bhatinov mask is an essential bit of kit & not expensive (look on Ebay, there's a chap in Melb who 3d prints them & I know he has one for an 8" Meade SCT coz I gave him the specs to make me one - cost you about $16 posted)... it will help you immensely in achieving tight focus...

Another extremely helpful acquisition would be a 0.63x focal reducer which is designed to work with these SCT's. Both the Meade & Celestron ones will work (not the Celestron one for the Edge HD). These are not particularly cheap new but, they do appear in the classifieds from time to time at a much more reasonable price. A well corrected reducer will also tighten up your stars.

Cheers & enjoy the journey

Last edited by Outcast; 22-12-2020 at 10:17 AM.
Reply With Quote