UK skies often mean imaging under less than optimal conditions – this year has been particularly poor in terms of clear skies. It seems all we’ve had is rain and cloud so, whenever the skies are clear, I need to get out and have a go. And so it was last Wednesday, when a clear 12 hour night clashed with a 61% moon phase. I decided to throw caution to the wind and try and image the Great Nebula of Orion, NGC 1976. I had just received a 0.85x field flattener and reducer for my 80ED scope and wanted to test how it worked. I decided to try for 5 hours on Orion, once the moon had moved further towards the western horizon, and hoped that my clip-in CLS filter would be effective.
I also decided to shoot at two exposures and try out PixInsight’s HDR image process to try and bring out the core while still capturing the outer nebulosity.
I shot the following sequence:
30 x 10s
10 x 300s
No darks (but extreme dithering)
The average sensor temperature was 4c for the 10 secs and 13c for the longer 300 sec exposures. I also paused for 45 secs between each frame, and dithered every other frame on high settings.
The star field turned out really well – pretty round right to the extremities – and the SNR was good, especially on the 300 sec subs.
My processing in PixInsight was a little unusual – I’m not sure how it ended up as vibrant as it did; I did saturate but not a lot – the data just seemed to go in this direction. It might be because i have started using the ArcSin stretch process which seems to retain colour a lot, especially reds which probably amplified the results from my modded DSLR. Whatever the reasons, I do like the result! I will have another go at processing it using a more conventional workflow, but I am definitely keeping this as an alternative take on NGC 1976.
A more conventional presentation on my Astrobin Account
It was quite flattering that my image got selected by Flickr on the 29th to appear on their end of year Explore feed so that opened up my Flickr account to a whole new audience.