Horsehead and Flame Nebulae in Orion 16 Dec 2017

[The Thing]

That perennial favourite target for the time of year. 85x120s@iso800. I messed about with this and had several iterations at stacking it before realising that a lot of the subs had clouds in them! Too much reliance on the software. I have another 200ish subs to process from different nights in December, most of better quality than this, but don't seem to have time to sit and process them due to puppy sitting and wind damage repairs etc. etc.. This version is half size (click the image to get the big version).

Image date, time and location:   2017-12-16 23:00 Manche, France
Telescope aperture and focal ratio:   TS1506UNC f4 Newtonian, TS Komakorr corrector
Camera and filters used:   Canon 1100d defiltered, Astronomik UV-IR filter
Processing applied:   Pixinsight, GIMP, Irfanview

[JohnP]

Wow Duncan pretty amazing - your imaging/ processing skills have really gone up several notches in last few months. Colours look spot on, detail looks amazing - only comment I can make is perhaps looks a little low on brightness or something like that - kinda looks a bit flat - could be 'punchier'

Absolutely superb though - really like it & congrats on the 25 years btw...

John

[Carole]

Lovely lot of detail there Duncan, lovely colours, but somehow the white element of the image has got lost and replaced with colour.  Not quite sure how this has happened, but if you can rectify that it will be an excellent image.

I have been imaging the HH the last two nights (braved the sub zeros temperatures), but was unable to get any decent luminance I guess due to the Moon and my LP location but got bags of Ha.  Will be processing it in the next day or so, if I can get anything like yours I will be well happy.

Carole

[The Thing]

Thanks John.

Carole, I used PixInsights Photometric Colour Calibration (PCC) tool which uses real star colour measurements and compares them to the version in he image and applies a correction based on an 'average spiral galaxy' colour base. Then Mark's Asinh Stretch tool. The PCC is a bit temperamental and of course scientific star colour measurements aren't exactly RGB values. Still, it looks pretty if a bit noisy. I am now going to see if I can process the other 200 subs, which should be better as they were taken later in the night when the streetlights were out.

[Carole]

I am now going to see if I can process the other 200 subs

You have another 200 DSLR subs???

Blimey your laptop is working hard as well as you.

Carole

[MarkS]

Wow! That is a brilliant image - I had to look twice - I almost thought it was one of my own!

The colours are spot on and I love the diffraction spikes.  The dust is coming out really nicely.  For a humble Canon camera that is a lovely result.  The fast scope is clearly a good match for the camera.

A couple of suggestions to improve the image further:
1) To get rid of the pink star cores, bring down the white point using "levels" to force the green to saturate, thus making the core white.  Do this before the stretch.
2) Don't use arcsinh stretch for the whole stretch but go most of the way with arcsinh and then finish off with a traditional curves stretch.  The end result will be slightly less colour saturated - but it's a matter of personal taste.

All in all it'll be very difficult to improve much on that very fine result!

Mark

[The Thing]

Thanks Mark, just about to upload a new version with different subs in a new thread. It's much better than this but I hadn't read your note about pink stars , don't know if there are any to worry about as  I haven't looked!