This little project has been going on since December.
Has taken a while to capture the data with interruptions due to work, weather etc.
Presented some processing challenges as well due to the dynamic range.
Will be interested in the thoughts of forum members as to how the final image has turned out.
Details are: Acquisition:
rgb - 15 x 600s, Ha 23 x 1800s
(I did take luminance but finished up not using it as the Ha provided much better detail),
rgbHa - 10 x 300s (added in using the PI HDR Combo tool)
Hardware:
QSI683WS-8
Canon EOS F1.4 Lens @ f5.0
Skywatcher EQ8 mount
Software:
Capture in Maxim DL
Post processing in Pixinsight
Finish off with PS CS6
Well I guess that I did say that I welcomed critique. A sturdy response for a sturdy image. Thanks Mike.
You're welcome, this image game is so much fun huh? We all image the same sorts of things and come up with many different results, that's the game, the journey, it's art, it's science, it's taste...it's great
You've made Barnard's Loop very real. Impressively deep. First images I saw of it (long time ago, film) it required "averted imagination" to see it.
It was fun hunting around and identifying horsehead, flame, etc.
Tough decision as to whether to let those things burn out, so as to give a feel for how very faint the loop is (nobody would call the horsehead's nebula bright), or whether, as you've chosen, to make it more of a map or diagram, with the attendant inevitable posterization, but where staggeringly bright and staggeringly dim can both be seen in the one image. A successful technical adventure.
Wow! That's a lot of data. Very deep. I suspect you could extract more details from the loop itself. If the image scale allows it. Did you use noise reduction or sharpening? It might have muted the fine details. Great effort regardless.
I wonder if a more gentle approach to contrast would make it appear more real and less posterized. The clipped blackpoint is masking all the fine dust in that region, and the details appear a bit soft.
Thanks everyone for your responses. They have certainly captured the essence of my thoughts and challenges throughout this exercise. I have been keen to capture a solid image of Barnard's Loop for some time and was never happy with the results achieved with my DSLR. It is certainly apparent (whether I realised it or not previously) that I was looking for the 'punchy' effect and it is clear from the responses that I have achieved this. Sacrificing contrast in lieu of detail was something I pondered in the processing as I vacillated between fainter detail vs. emphasising the loop and how to manage this. Marc's question on noise reduction has made me think about ways that I may approach this differently or at different stages in the processing which will assist in retaining faint detail.
I will redo this area next summer I am thinking as I have learnt from this exercise. One thing will be to capture the Ha data at 1x1 and to capture additional 60 second subs to assist with dynamic range in the saturated regions. All in all I think that Mike (Placidus) has summarised it well by describing this as a technical adventure. That it was and a most entertaining one as well. In the mean time I must move on to other projects like getting my GSO RC10 up and running.
So many projects and so little time ....
Clear skies.
Last edited by Ryderscope; 19-02-2015 at 11:26 AM.
A bit overprocessed for my taste too, but with more subtle processing I reckon you'd have a fantastic image.
Cheers,
Rick.
Thanks Rick, I have actually started working on another process of this image and if the current cloudy / rainy weather keeps up I may just get it done soon.
Like the others say, but congrats on using your camera with an EOS lens, not done that often around this place.
... and I intend to exercise a few of my Canon lens as time permits. I have a 200mm lens that I want to try out (after I get my RC10 going that is). I have been keen to try out some widefield imaging for some time which is why I bought the lens adapter for the QSI.
has had the crap processed out of it, so not too pretty 
... but sheesh! strongest looking Barnards loop I have seen I recon, well done 
Thanks Mike.
