Orpington Astronomical Society

Astronomy => Astrophotography => Topic started by: RobertM on Jan 21, 2016, 20:46:24

Title: Part of the Heart nebula (IC1796 to Melotte 15)
Post by: RobertM on Jan 21, 2016, 20:46:24
5hr 40 mins of Ha with a 3nm filter but I really need double the subs for more detail.  Sorry it's mono at the moment as I'm still collecting OIII.  I should have started with OIII and done the Ha with the moon around but you have to take what you can get !

Processed in Pixinsight: Deconvolution, Histogram stretch, Denoise, HDR Multiscale & Curves.

Not sure if I've overcooked this a bit, anyway I hope you like it.

(https://c2.staticflickr.com/2/1613/24443159211_21a2654e77_b.jpg)

Full res (cropped a bit): https://c2.staticflickr.com/2/1613/24443159211_f6078f4a83_o.jpg (https://c2.staticflickr.com/2/1613/24443159211_f6078f4a83_o.jpg)

Robert
Title: Re: Part of the Heart nebula (IC1796 to Melotte 15)
Post by: MarkS on Jan 21, 2016, 21:04:11
That's looking very good to me Robert.

How many layers did you use for your HDR Multiscale?

Mark
Title: Re: Part of the Heart nebula (IC1796 to Melotte 15)
Post by: RobertM on Jan 21, 2016, 22:14:44
Thanks Mark.  It was 2 iterations of 10 layers, everything else default.

Title: Re: Part of the Heart nebula (IC1796 to Melotte 15)
Post by: Fay on Jan 21, 2016, 22:16:38
Nice Robert, I must have a look at Pixinsight, i presume you can use just bits of it?
Title: Re: Part of the Heart nebula (IC1796 to Melotte 15)
Post by: MarkS on Jan 21, 2016, 22:23:27
Quote from: RobertM
Thanks Mark.  It was 2 iterations of 10 layers, everything else default.

I need to try it on my recent Orion image to get a bit more contrast - especially in the Trapezium area.  But I want to take the subtle approach.  I have seen some bad examples where people have really overdone it to extract the last bit of detail but leaving a ghastly result.  Some image have a very definite "PI HDRMultiscale" look about them.
Title: Re: Part of the Heart nebula (IC1796 to Melotte 15)
Post by: RobertM on Jan 21, 2016, 22:57:11
Quote from: Fay on Jan 21, 2016, 22:16:38
Nice Robert, I must have a look at Pixinsight, i presume you can use just bits of it?

It has lots of 'bits' but I only use a few.  Processing can be quite quick if you find the right modules and use the right settings (which aren't usually the defaults !).  Obviously, as always, it helps if the data is good to start with.

Mark, yes I know exactly what you mean.  Too few or two many iterations produced a terrible result but in themselves those results can be used to demonstrate structure.  For mono (Ha) images I'm finding 8-10 layers x2 works best.

Robert