#1  
Old 15-05-2021, 10:57 PM
Greggles (Gregory)
Registered User

Greggles is offline
 
Join Date: Aug 2017
Location: Sydney, Australia
Posts: 60
Is this vignetting normal?

Hi all,

I photograph with a Nikon D5500 connected to a 10" F5 dobsonian on a DIY EQ platform. Recently i changed the bolts to move my primary mirror up the tube in order to achieve focus with my DSLR with out using a 1.5 barlow.

After doing this i feel like the vignetting has been a lot worse when stretching the image but i'm unable to compare to my old images as they are on a HDD in storage at the moment.

Can moving the mirror up cause more vignetting? or does the 1.5 barlow crop out some of the vignetting?

below is a link to an unedited stack (sequator) and a a single light frame. Just wondering if this seems nomral or excessive after the stack is stretched?

https://drive.google.com/drive/folde...IH?usp=sharing

Thanks Every one,

Greg
Reply With Quote
  #2  
Old 15-05-2021, 11:54 PM
Greggles (Gregory)
Registered User

Greggles is offline
 
Join Date: Aug 2017
Location: Sydney, Australia
Posts: 60
thanks for the reply Glen. ill probably just have to live with it for now which sucks.

Really struggling to get a final image with the stacked image below. If any one wants to have a go at it, feel free.
Reply With Quote
  #3  
Old 16-05-2021, 10:52 AM
Nikolas's Avatar
Nikolas (Nik)
Dazed and confused

Nikolas is offline
 
Join Date: May 2012
Location: Melbourne
Posts: 2,177
I had a play with it in photoshop, the vignetting is normal but if you take flats that can be calibrated out
I used Gradient exterminator in photoshop which did a great job on the vignetting. The rest was just a quick process, you need a coma corrector which may help
Attached Thumbnails
Click for full-size image (sequator-m4.jpg)
68.9 KB28 views
Reply With Quote
  #4  
Old 16-05-2021, 11:25 AM
ChrisV's Avatar
ChrisV (Chris)
Registered User

ChrisV is offline
 
Join Date: Aug 2015
Location: Sydney
Posts: 1,556
+1. Flats are your friend
Reply With Quote
  #5  
Old 16-05-2021, 12:35 PM
Greggles (Gregory)
Registered User

Greggles is offline
 
Join Date: Aug 2017
Location: Sydney, Australia
Posts: 60
Wow, Quick process? this looks great. I guess I need a lot of improvement on my post processing with photoshop!

Flats, Noted.. Might run out today and grab and artists tracing light board to take flats. seems like one of the easiest methods.

Regards,

Greg


Quote:
Originally Posted by Nikolas View Post
I had a play with it in photoshop, the vignetting is normal but if you take flats that can be calibrated out
I used Gradient exterminator in photoshop which did a great job on the vignetting. The rest was just a quick process, you need a coma corrector which may help
Reply With Quote
  #6  
Old 16-05-2021, 05:43 PM
Nikolas's Avatar
Nikolas (Nik)
Dazed and confused

Nikolas is offline
 
Join Date: May 2012
Location: Melbourne
Posts: 2,177
Quote:
Originally Posted by Greggles View Post
Wow, Quick process? this looks great. I guess I need a lot of improvement on my post processing with photoshop!

Flats, Noted.. Might run out today and grab and artists tracing light board to take flats. seems like one of the easiest methods.

Regards,

Greg
Quick process ie colour balance and chroma noise reduction after some stretching
you had some good data there
Reply With Quote
  #7  
Old 16-05-2021, 11:14 PM
Greggles (Gregory)
Registered User

Greggles is offline
 
Join Date: Aug 2017
Location: Sydney, Australia
Posts: 60
Thanks Mate,

Although i feel like an idiot... I just used flats for the first time... why on earth did I wait so long to use flats! the results where awesome and editing is so much easier when not having to deal with the gradient! :O

Quote:
Originally Posted by Nikolas View Post
Quick process ie colour balance and chroma noise reduction after some stretching
you had some good data there
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 02:08 PM.

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