Go Back   IceInSpace > Equipment > Software and Computers

Reply
 
Thread Tools Rate Thread
  #1  
Old 06-09-2008, 07:57 PM
g__day's Avatar
g__day (Matthew)
Tech Guru

g__day is offline
 
Join Date: Dec 2005
Location: Sydney
Posts: 2,888
Is it MaximDL that has a Make stars rounder function?

I remember doing this once - but not sure what software package I used (I think it was MaximDL v4.6) but not sure if it was a plug-in.

Anyone know what to use to address (correct) coma using software?

I thought it might have been Rod Wodaski's DeBloomer for MaximDL - but it crashes for me (Subscript out of range) so I can't tell for sure - http://www.newastro.com/downloads/products.php

Thanks,

Matt

Last edited by g__day; 06-09-2008 at 08:17 PM.
Reply With Quote
  #2  
Old 06-09-2008, 08:55 PM
Alchemy (Clive)
Quietly watching

Alchemy is offline
 
Join Date: Jul 2007
Location: Yarra Junction
Posts: 3,044
not sure , but jase says .... or my interpretation of what he said was..... that digital development gives that effect

might have to do a search to confirm that though.
Reply With Quote
  #3  
Old 06-09-2008, 10:55 PM
jjjnettie's Avatar
jjjnettie (Jeanette)
Registered User

jjjnettie is offline
 
Join Date: Feb 2005
Location: Monto
Posts: 16,741
MaxIm DL has the debloomer.
You can get the Star Rounder plugin for PhotoShop.
Reply With Quote
  #4  
Old 06-09-2008, 11:08 PM
jjjnettie's Avatar
jjjnettie (Jeanette)
Registered User

jjjnettie is offline
 
Join Date: Feb 2005
Location: Monto
Posts: 16,741
AstroPlugins "Star Rounder" v1.03 2005 James Ryan
That's the one I have.
Find it here
http://www.grekalova.com/photo_Astroplugins.html
along with other goodies.
Reply With Quote
  #5  
Old 06-09-2008, 11:46 PM
g__day's Avatar
g__day (Matthew)
Tech Guru

g__day is offline
 
Join Date: Dec 2005
Location: Sydney
Posts: 2,888
Thanks - Debloomer crashes and Star Rounder doesn't seem to do anything
Reply With Quote
  #6  
Old 07-09-2008, 09:03 AM
jjjnettie's Avatar
jjjnettie (Jeanette)
Registered User

jjjnettie is offline
 
Join Date: Feb 2005
Location: Monto
Posts: 16,741
Here's an example of what Star Rounder can do.
I moved all the adjustment sliders to the far right to fix this pic.
Attached Thumbnails
Click for full-size image (before star rounder.jpg)
47.6 KB83 views
Click for full-size image (after star roundert.jpg)
43.7 KB84 views
Reply With Quote
  #7  
Old 08-09-2008, 11:42 PM
g__day's Avatar
g__day (Matthew)
Tech Guru

g__day is offline
 
Join Date: Dec 2005
Location: Sydney
Posts: 2,888
Hmmm it did something. Moving all the sliders to the right helped - but 1/3 of the fainter stars then disappeared!
Reply With Quote
  #8  
Old 09-09-2008, 07:26 AM
jjjnettie's Avatar
jjjnettie (Jeanette)
Registered User

jjjnettie is offline
 
Join Date: Feb 2005
Location: Monto
Posts: 16,741
Ooops.
Reply With Quote
  #9  
Old 09-09-2008, 01:26 PM
g__day's Avatar
g__day (Matthew)
Tech Guru

g__day is offline
 
Join Date: Dec 2005
Location: Sydney
Posts: 2,888
In fact look at your two shots - some stars disappear and some almost disappear!
Reply With Quote
  #10  
Old 09-09-2008, 03:29 PM
jase (Jason)
Registered User

jase is offline
 
Join Date: Sep 2006
Location: Melbourne, Victoria
Posts: 3,916
Sorry, just saw this post...been busy with work.

Before I digress, we should all acknowledge that there is no magical smoke and mirrors algorithm to make shotty stars look perfect. We are talking about pin point sources of light which are best controlled through good optics and guiding amongst other things. Manipulating stars in post processing should ideally be an act of enhancement not recovery. Try not to get into the situation of the latter.

Quote:
Originally Posted by Alchemy View Post
not sure , but jase says .... or my interpretation of what he said was..... that digital development gives that effect

might have to do a search to confirm that though.
Close... MaximDL has a Kernel Filter which can be invoked by deconvolution or Digital Development function. You can configure the "User Defined" Kernel filter to sharpen stars in a non uniform manner. This can be used to alter edge to centroid mapping. A word of warning, from experience this method can be a little hit and miss. There is an assumption that all stars across the field have the same problem - common with guiding errors - difficult for optical errors such as off axis coma. There is no "selectiveness" in the routine - all stars are given the same treatment. However, you can work around this by creating different Kernel filters and integrating them into a single image using masks. You'll pull your hair out in the process - not for the faint hearted. More information is available here; http://www.princeton.edu/~rvdb/images/deconv/deconv_MaximDL.html
Reply With Quote
  #11  
Old 10-09-2008, 09:06 AM
g__day's Avatar
g__day (Matthew)
Tech Guru

g__day is offline
 
Join Date: Dec 2005
Location: Sydney
Posts: 2,888
Jase et al - many thanks!

I think I am back to reposition the rotten focal reducer in the Lumicon OAG to see if I can kill this coma - shots where perfect (coma-wise) before this arrived.

Lumicon say it shouldn't occur - but my OTA has a 3" long Meade electronic focuser before the OAG - maybe that is moving the focal range to a position they just didn't test well enough. Maybe the focal reducer just doesn't sit in the OAG absolutely correctly - who knows?

If a star looks streaked at the edges of your shot I'm suprised a custom plug in doesn't detect this and make coma affected stars more round. Worse before a PC crash and software re-load I believe MaximDL use to do this and do it well - it would grab suspect stars then process and leave egg shaped stars more round.
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 03:37 AM.

Powered by vBulletin Version 3.8.7 | Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
Advertisement
Bintel
Advertisement