Go Back   IceInSpace > Beginners Start Here > Beginners Equipment Discussions

Reply
 
Thread Tools Rate Thread
  #1  
Old 11-06-2021, 12:43 PM
evltoy (Wayne)
Registered User

evltoy is offline
 
Join Date: Sep 2020
Location: Melbourne
Posts: 115
Back focus with my DSLR and SCT with reducer

Hello All,

I hope everyone is keeping well

As some may know, I have been battling with getting the right back focus distance with the introduction of a x.63 Celestron Corrector/reducer on my 8" SCT. Last night I was able to sneak in 2hrs of testing while the skies were somewhat clear.

Here is what I did.
1) Using my Alt/AZM mount align etc..
2) Using a Bahtinov mask, get the right focus on a bright start
3) Slew to NGC104 and took the best 30sec exposure
4) Change distance down by 5mm
5) repeat steps 2-4

The only thing I didnt do is frame up the target like for like. Should I have done this?

Anyways I have attached the single shot images for review. If you have the time please have a look and tell me which image feels right or getting close to perfect.

The setup is a Celectron 8" SCT with Celestron .63 Corrector/reducer, 2" rings to a Nikon D600 (using DX mode).

Cheers
Wayne
Attached Thumbnails
Click for full-size image (Single__D60_1308_back_fouse_testing_2021-06-10_30s_ISO800_50mm__NA.jpg)
141.5 KB43 views
Click for full-size image (Single__D60_1314_back_fouse_testing_2021-06-10_30s_ISO800_40mm__NA.jpg)
143.7 KB43 views
Click for full-size image (Single__D60_1319_back_fouse_testing_2021-06-10_30s_ISO800_35mm__NA.jpg)
137.2 KB46 views
Click for full-size image (Single__D60_1324_back_fouse_testing_2021-06-10_30s_ISO800_30mm__NA.jpg)
132.0 KB42 views
Click for full-size image (Single__D60_1330_back_fouse_testing_2021-06-10_30s_ISO800_25mm__NA.jpg)
134.8 KB27 views
Click for full-size image (Single__D60_1335_back_fouse_testing_2021-06-10_30s_ISO800_20mm__NA.jpg)
139.2 KB31 views

Last edited by evltoy; 11-06-2021 at 12:53 PM. Reason: spelling
Reply With Quote
  #2  
Old 14-06-2021, 12:54 PM
AdamJL
Registered User

AdamJL is offline
 
Join Date: Sep 2010
Posts: 869
Hi Wayne

I would say the two sharpest are these:

http://www.iceinspace.com.au/forum/a...e.php?a=276409
http://www.iceinspace.com.au/forum/a...e.php?a=276410

hard to choose between those two.
Reply With Quote
  #3  
Old 15-06-2021, 02:41 PM
evltoy (Wayne)
Registered User

evltoy is offline
 
Join Date: Sep 2020
Location: Melbourne
Posts: 115
Hey Adam,

Thanks for taking out the time to look & comment. I appreciate you helping me out.

I too picked one you did
https://www.iceinspace.com.au/forum/...e.php?a=276410

But I went the other way on my second
https://www.iceinspace.com.au/forum/...e.php?a=276411

My main focus was trying to find the most roundest stars on the outer sections of the image.

Cheers
Wayne
Reply With Quote
Reply

Bookmarks

Thread Tools
Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +10. The time is now 09:16 AM.

Powered by vBulletin Version 3.8.7 | Copyright ©2000 - 2021, Jelsoft Enterprises Ltd.
Advertisement
Bintel
Advertisement
Limpet Controller
Advertisement
Testar
Advertisement
NexDome Observatories
Advertisement
Astronomy and Electronics Centre
Advertisement