Orpington Astronomical Society

Astronomy => Astrophotography => Topic started by: julian on Mar 06, 2012, 22:01:13

Title: M65 M66 NGC 3628 Leo Triplet from February DSC
Post by: julian on Mar 06, 2012, 22:01:13
55 x 5mins (4hours 35minutes) 1600 ISO Modified Canon 40D - CLS filter
Skywatcher MN190 guided on EQ6 pro with QHY5 and PHD


(http://farm8.staticflickr.com/7059/6960002627_e57aa6939f_b.jpg)


Link to original size

http://farm8.staticflickr.com/7059/6960002627_72d98e4cd6_o.jpg
Title: Re: Leo Triplet from February DSC
Post by: MarkS on Mar 06, 2012, 22:39:33

Very nice scale Julian and I like the colours.

You've captured a lot of detail and you've clearly pulled out as much faint stuff as possible.  The galaxy cores look slightly overblown - I wonder if that is in the acquisition (unlikely) or the processing (more likely).

Those galaxies certainly make a pleasing composition!

Mark
Title: Re: M65 M66 NGC 3628 Leo Triplet from February DSC
Post by: julian on Mar 07, 2012, 00:25:15
Thanks Mark
Just did a total reprocess


(http://farm8.staticflickr.com/7199/6814227492_7f3ee59cd0_b.jpg)


Link to original size

http://farm8.staticflickr.com/7199/6814227492_ca305bb540_o.jpg
Title: Re: M65 M66 NGC 3628 Leo Triplet from February DSC
Post by: Rocket Pooch on Mar 07, 2012, 07:36:29
Hi Julian,

Thats very nice.

Round stars and all.  Just wondered if the cores are intact in the galaxies ?  If they are you could probably do with creating two layers in photo shop one for the background and one for the galaxies, that way you can balance the images better.

Also I saw on Marks horsey some what I thought was thermal noise, also its here, is this something DSLR's do?

Chris
Title: Re: M65 M66 NGC 3628 Leo Triplet from February DSC
Post by: MarkS on Mar 07, 2012, 08:25:40

Chris, my horsey did not contain noticeable thermal noise - it was dominated by sky flux noise.  Almost certainly that is also the case in Julian's image.

However, the background noise of a one shot colour camera does have a different characteristic to that of a mono camera due to interpolation effects during de-bayering.  It is something I want to understand better at some stage.

Julian - that's a good reprocess.

Mark
Title: Re: M65 M66 NGC 3628 Leo Triplet from February DSC
Post by: RobertM on Mar 07, 2012, 12:41:36
That's really excellent Julian, I especially like the reprocess though you should be careful not to push the contrast too much.  I agree with Chris about the processing.  Using a layer for the background would help reduce the bloat around that bright star and give you better control of the fainter parts of those galaxies.

Robert

Title: Re: M65 M66 NGC 3628 Leo Triplet from February DSC
Post by: Fay on Mar 07, 2012, 16:34:44
That is very good Julian!!!!!! you have done well!!
Title: Re: M65 M66 NGC 3628 Leo Triplet from February DSC
Post by: PhilB on Mar 07, 2012, 19:29:48
Tried these the other week myself - made a hash of it :roll: This is like alot  8)