Orpington Astronomical Society

Astronomy => Astrophotography => Topic started by: mickw on Jul 15, 2011, 11:39:14

Title: M45 revisited
Post by: mickw on Jul 15, 2011, 11:39:14
Never really happy with the processing so I thought I'd dig out M45 from Rother Valley last October give another go.
Still Burgess 91, Canon 350D (the pre destruction model) unguided, this time processed CS3

(http://gallery.orpington-astronomy.org.uk/albums/userpics/10049/normal_m45_DSS-V2.jpg)

The original's here for comparison

http://gallery.orpington-astronomy.org.uk/albums/userpics/10049/normal_M45_800_15x120_DSS_CS3.jpg

Was it worth the effort ?
Title: Re: M45 revisited
Post by: RobertM on Jul 15, 2011, 12:54:06
I think so.  You've picked up a gradient towards the bottom right but it's much better balanced and there's much more nebulosity showing.
Title: Re: M45 revisited
Post by: mickw on Jul 15, 2011, 13:06:31
Thanks Robert, I think the gradient is amp glow I thought I'd killed it on the tif but it seems to have sneaked back in the jpg
Title: Re: M45 revisited
Post by: PhilB on Jul 15, 2011, 21:08:04
You've certainly pull out more of the wispy stuff. I like it
Title: Re: M45 revisited
Post by: MarkS on Jul 16, 2011, 12:19:43

It was definitely worth the trouble Mick - you've pulled out a lot of extra faint nebulosity.  Nice one!

Mark
Title: Re: M45 revisited
Post by: mickw on Jul 16, 2011, 17:05:07
Thanks for that, wasn't too sure about it being overdone.
Title: Re: M45 revisited
Post by: Carole on Jul 20, 2011, 14:57:55
Looks much better than  the original process Mick, much more nebulosity showing through.

Carole
Title: Re: M45 revisited
Post by: mickw on Jul 24, 2011, 10:40:31
OK,question time.
I've just had my first attempt at Gradient Removal using Layer Mask  :o
Process - Created duplicate layer, cloned out the bright stars and nebulosity but left the bright area in bottom right corner (which I think is amp glow), then flattened using Difference then a final tweak in curves to bring up the nebulosity.

Did I do it right ?
Have I overdone it ? (I think yes)
Is it an improvement ?
Answers on a postcard  :)

(http://gallery.orpington-astronomy.org.uk/albums/userpics/10049/normal_m45_DSS-V2-grad2.jpg)
Title: Re: M45 revisited
Post by: Fay on Jul 24, 2011, 13:37:38
I think you have lost a bit of the nebulosity, on the second one,  Mick, although your first reprocess was very good
Title: Re: M45 revisited
Post by: mickw on Jul 24, 2011, 14:00:39
Hmm inclined to agree, I've re-read the "how to" and think I know where I went wrong - I'll give it another go before I lose interest  ;)

*I think I should have a bit lot more practice with this Layers malarky - I can see the difference it makes but am clueless about how to control it  :oops:
Title: Re: M45 revisited
Post by: The Thing on Jul 24, 2011, 23:58:16
Hi Mick,

I've been playing around with 'Olympus Background Subtraction Toolkit' which I think is aimed at users of Olympus microscopes who want to remove gradients from their images. Downside is it doesn't like TIFs. I am going to give it a go with tonights results and will post before and after images.
Title: Re: M45 revisited
Post by: mickw on Jul 25, 2011, 10:38:31
Sounds promising