Here's an updated two frame mosaic of the main part of the constellation of Orion.
Clickable for an uncompressed 1024 pixel wide version.
The original is 4096 x 6596 pixels and is available here (Link updated to version 7). (4MB).
My first attempt at combining RGB nebulosity with H-alpha, a process I found more than difficult and needs more practice I fear! Pretty much all of the deep red (Barnard's Loop etc.) is derived solely from the H-alpha data. PixInsight made combining the various RGB exposures to cover the high dynamic range of M42 relatively straightforward. PixInsight was used right up to production of the separate mosaics in both H-alpha and RGB and then PhotoShop was used to get rid of the H-alpha stars and add in RGB stars and the brighter nebulosity to allow some colour into the Sword and Flame nebulae. I really struggled with star bloat for the brighter stars as well as combining the H-alpha and RGB nebulosity data, yet more proof that I am near the bottom of the learning curve still.
Helpful tips on what I might do to improve the image are always welcome.
3 x 1000 second exposures in H-alpha for each frame
3 x 200 second exposures in each of R, G and B for both frames
3 x 40 second exposures in each of R, G and B for the bottom frame
3 x 5 second exposures in each of R, G and B for the bottom frame
Pentax 165mm f/2.8 lens plus FLI ML16803 camera
Update: Image now v6 and a link to the full resolution image added.