The Flame Nebula NGC 2024 is an emission nebula in the constellation Orion about 900 to 1,500 light-years away. The bright star Alnitak is the easternmost star in the Belt of Orion, shines energetic ultraviolet light into the Flame and this knocks electrons away from the great clouds of hydrogen gas that reside there. 
NGC 2023 is an emission and reflection nebula (one of the largest in the sky). The Horsehead Nebula, also known as Barnard 33 is one of the most famous dark nebula in the sky and is challenging to visually recover, typically requires  at least 10" of aperture and a Hydrogen Beta filter.

I wanted to get more data on this field but the weather has been most un-cooperative so getting 8 x 5 minute exposures in SII HA and OIII for the two fields of the mosaic was basically serendipity. A rare social visit and the promise of no rain meant I was running the scope in my back-yard remotely for most of the evening using Google Remote Desktop and a hot spot on my phone. I can't recommend that piece of software enough; basically it is free and IMHO best in class for this sort of thing.

My first processing efforts in Pixinsight with Normalised Scale Gradient delivered the usual red version but in the end I prefer this palette.
This version is Drizzled which precluses NSG for now and was my first look at StarXTerminator which seems pretty good and much quicker and provides a cleaner starless image than StartNet++ so it look like RC Astro will be getting my money as it's not free.

Alnitak is a real handful in the image! The 127is Petzval system has major issues with reflections off the extra objective when any bright object is in the field so the GAME script came in very handy dealing with that. Sadly it is the only refractor I have used that has that issue but the 127 compensates somewhat by having beautifully clean resolution and the image scale of 1.15 arcseconds per pixel with the QSI 690 CCD has kept me away from switching to CMOS (for now).

If I can get my sub count up and I can work with more data I will see how that goes, but for now I like this.