Horsehead - New Approach

[Stub Mandrel]

The Horsehead nebula with Alnitak in frame, is the only target where I have suffered from reflections in my Skywatcher Coma Corrector. As well as a 'blue blur' diagonally opposite Alnitak, there was a refraction spike reflected in from the edge (probably not by the CC) and some severe gradients. A big shame with 200 minutes of 120 second subs showing loads of colour.

I tried loads of different methods to attack the data and have come back again and again. In the end I use Photopaint to extract the red data and create a synthetic luminance channel to go on top of my best previous attempt, at about 60% transparency it gave a good result. I couldn't get a start mask to work without bad artefacts, so to horrify PI users I added a luminance layer for the bright stars and used a mask to control and add detail to the brightest stars, so Alnitak is showing as a binary.

Finally I denoised a copy and mixed it in so as not to completely remove noise and make it appear sterile. Finally I masked over a sharpened version to gently enhance the nebulosity.

[Guest]

A very nice image and processing, love the colours..

 

Cheers

 

Martin

[Skyline]

A beautiful piece of work regardless of your reflection issues