It is currently Thu Feb 22, 2018 6:37 am

All times are UTC




Post new topic Reply to topic  [ 2 posts ] 
Author Message
 Post subject: IRIS to the rescue!
PostPosted: Thu Aug 09, 2012 12:49 pm 
Offline
Member
User avatar

Joined: Mon Oct 12, 2009 6:47 pm
Posts: 1249
Location: Bolton
Last night I was testing a different combination of webcam, computer and software, and although everything looked OK on the screen at the time, when I came to look at the files this morning I found something very strange:
Attachment:
File comment: all the Green & Blue fields were inverted in this entire sequence of images
colourfault.jpg
colourfault.jpg [ 39.33 KiB | Viewed 2451 times ]

But a couple of hours after deleting these files, I thought of a way to recover them using IRIS.
So having restored them from the Recycle Bin I set about the rescue misson.
I loaded each file in turn, then split the Red, Green & Blue fields (as Gerald demonstrated the other evening), flipped the G & B and then re-merged them.
Using the IRIS Looper utility (http://www.wilmslowastro.com/software/downloads/IrisLooper_v04.zip) it was easy to run the following loop of instructions:
load image
split_rgb r g b
load g
mirrorx
save g
load b
mirrorx
save b
merge_rgb r g b
save image

on each of my 25 lights and 24 calibration frames - it only took a few minutes.

Then I was able to follow the usual processing work-flow to obtain this image:
Attachment:
File comment: M27 planetary nebula, imaged before the sky was properly dark.
25x 30-sec, plus 12 each offset & dark calibration frames.

m27_rescue.jpg
m27_rescue.jpg [ 25.56 KiB | Viewed 2451 times ]

So the morals of the story are:
  • don't throw away "useless" images - you may eventually discover a way to rescue them!
  • it's well worth the time spent learning to use the IRIS program
  • use the not-so-dark nights to practice with your camera, computer & software, so you'll have everything sussed in time for the winter...


Top
 Profile  
 
 Post subject: Re: IRIS to the rescue!
PostPosted: Thu Aug 09, 2012 1:00 pm 
Fantastic turnaround there Ross... A lesson for us all - never doubt the power of IRIS!

I think i'll have a dance with my 'awful M57' shots.


Top
  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 2 posts ] 

All times are UTC


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
cron
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group