Orpington Astronomical Society

Astronomy => Astrophotography => Topic started by: Carole on Apr 22, 2010, 00:03:06

Title: M13 Kelling Heath 16.4.2010
Post by: Carole on Apr 22, 2010, 00:03:06
Managed to capture M13 on the Friday and also small NGC 6207 is on the left of the picture:

Canon DSLR EOS 450D, 800 ISO, CLS filter, Megrez 72 APO, CG5 GT 1 hour 9 mins (13 x 3 mins + 6 x 5 mins + D,F,B)
Processing in DSS and photoshop

(http://carolepope.amateur-astronomy.org/_wp_generated/wp3f8dfd80_0f.jpg)
Title: Re: M13 Kelling Heath 16.4.2010
Post by: MarkS on Apr 22, 2010, 06:25:15
Carole,

That looks really good - definitely your best image so far.  Its always very satisfying to catch a faint fuzzy in the background.

Is that a crop of the whole frame?

I thought you said it was out of focus? It doesn't look obviously out of focus to me.

Check your 3min frames to see if the core is burnt out or not.  If the core is not burnt out, create a separate image from the 3min frames and merge it into this one using layers, so the final image has visible stars in the core.

Well done!

Mark 
Title: Re: M13 Kelling Heath 16.4.2010
Post by: Carole on Apr 22, 2010, 08:37:46
Hi Mark,

It is slightly out of focus if you zoom in more.  But we realised what was going wrong after the event.  i.e. forgot to lock draw tube after focussing accurately - duh!, (Must try to remember next time).

Actually the main image is less burnt out in the core, but it's a balancing act with trying to show more in the sky around the cluster or burning out the core slightly.  I did have a go at trying to combine the two but wasn't successful the first time.  Will have another go at it and post it if I manage to do both.

With all it's drawbacks I am pleased with it and I agree it's my best so far, although I think the excellent dark skies were partly responsible for that as well.  Also should have done more subs, I can't remember now why I didn't, I think it might have been because it took me so long to get started that it was 2.30 am by the time I finished this and was tired after the long drive and setting up etc. 

It's a crop, it's too small to show the full frame but in any case the stars around the edge are distorted.

Carole
Title: Re: M13 Kelling Heath 16.4.2010
Post by: The Thing on Apr 22, 2010, 16:01:44
I'm impressed. My last effort at M13 was dismal compared to this. I didn't do subs of differing exposures to have the option of the two image processing Mark is talking about - definitely advance technique!
Title: Re: M13 Kelling Heath 16.4.2010
Post by: Rocket Pooch on Apr 23, 2010, 08:30:56
Hi Carol,

Thats a lot better, your getting there.

Chris
Title: Re: M13 Kelling Heath 16.4.2010
Post by: RobertM on Apr 23, 2010, 08:49:34
That's looking really good Carole.  Definitely your best so far by a long way.
Title: Re: M13 Kelling Heath 16.4.2010
Post by: Mike on Apr 23, 2010, 08:54:54
Well done Carole. Globulars are notoriously difficult to get right.
Title: Re: M13 Kelling Heath 16.4.2010
Post by: Fay on Apr 23, 2010, 20:00:14
Must have a go at  some clusters, very nice Carole
Title: Re: M13 Kelling Heath 16.4.2010
Post by: Carole on Apr 23, 2010, 21:05:08
Thanks Mark, Chris, Mike, Robert, Fay and Duncan.

Carole
Title: Re: M13 Kelling Heath 16.4.2010
Post by: Carole on Apr 24, 2010, 12:12:48
QuoteCheck your 3min frames to see if the core is burnt out or not.  If the core is not burnt out, create a separate image from the 3min frames and merge it into this one using layers, so the final image has visible stars in the core.

I had a go at this but only a slight improvement (left = Before) (right = after merging the 3min only subs in the core). Done in PS layers.
(http://gallery.orpington-astronomy.org.uk/albums/userpics/10047/normal_M13_before_and_after_core_enhancement.jpg)
Title: Re: M13 Kelling Heath 16.4.2010
Post by: Carole on May 15, 2010, 21:16:44
Having nothing better to do with these constant cloudy skies (although tonight just might be OK - fingers crossed), I have had a go at reprocessing M13.

This is levels to make the sky a bit darker using select colour range/select inverse to keep the stars bight.

Not sure if this is an improvement, the cluster is certainly brighter.

(http://gallery.orpington-astronomy.org.uk/albums/userpics/10047/normal_M13_levels_and_selected_colour_range.jpg)

Carole
Title: Re: M13 Kelling Heath 16.4.2010
Post by: PhilB on May 16, 2010, 06:49:25
Having opened one copy of each in two browser tabs and then flicked between them I'd say it's a definite improvement, Carole.
Title: Re: M13 Kelling Heath 16.4.2010
Post by: Carole on May 16, 2010, 08:51:36
Thanks Phil.

So much you can do with processing, but it's just learning what and how and when not to overdo it. 

Carole

Title: Re: M13 Kelling Heath 16.4.2010
Post by: MarkS on May 16, 2010, 14:37:00

Definite improvement, Carole - that's looking a lot nicer.
Title: Re: M13 Kelling Heath 16.4.2010
Post by: Carole on May 16, 2010, 15:44:52
Thanks Mark. 

Carole
Title: Re: M13 Kelling Heath 16.4.2010
Post by: RobertM on May 16, 2010, 18:04:16
I'd have to agree Carole, it's definitely showing an improvement.

Robert
Title: Re: M13 Kelling Heath 16.4.2010
Post by: Carole on May 16, 2010, 19:02:07
Thanks Robert.

Carole