Still a preliminary result so far as processing is concerned but I thought I'd share my first Hα mosaic of the main stars of the constellation of Orion. The original is 4000 x 6500 pixels but I've linked to a 1024 pixel wide version here
and here is a forum friendly 1024 pixel high version to look at:
Once I'm fully satisfied with the image I'll update it and post full details but essentially what one is looking at is the large area of faint Hα emission which, as you can see, is much more extensive than the Sword
(M42) visible with the naked eye. The Flame nebula
is visible just to the left of the left-most star in the belt of Orion and the Horsehead nebula
lies below. The stars were added into the image from separate RGB exposures and I made an attempt to include the RGB data of the brightest nebulosity as well. That proved extremely tricky as, although PixInsight allowed me to easily composite 200, 40 and 8 second RGB exposures (HDR needed due to the extreme, er, dynamic range!!!), it took me quite a while to figure out how to coax PhotoShop into including that nebulosity together with the Hα in a way that wasn't totally gross! That compositing may still need more work and might actually benefit hugely from more narrowband imaging at emission lines other than that of Hα (that will be for next year) but the benefit even with the data I have right now is some natural colour from the Flame nebula and even a slightly fuzzy rendition, due to the small scale, of the Running Man nebula
. I'm not totally sure about the colour in M42 compared to the artificial colour I use for the Hα nebulosity - I'd hate to use that colour for the extensive Hα but am I justified in altering it inside M42 to match the Hα? So many decisions!
I'm also not too happy with the way the brightest stars bloated out so maybe I need to revisit the area and capture a full set of 40 second exposures of the whole constellation rather than the more limited set of such exposures I used to do the HDR of M42. A work in progress...Update:
The final result was posted here
P.S. My previous effort with a DSLR (here
) shows that my investment in time, money and, dare I say it, learning is starting to pay off. I still feel pretty close to the bottom of that learning curve, though.
P.P.S. Extra processing might have to wait as, after nine months, the new telescope (a TEC 140) has finally arrived. I'm in love...