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NGC7023 Iris nebula

Posted: Tue May 11, 2021 9:43 pm
by timh
I really like this reflection nebula and after accumulating frames here and there - from last November - and again now in May as Cepheus come around again have finally accumulated enough to make for a decent enough image.

Newtonian PDS200, Baader flattener (F 5.0), Pegasus cube focuser all on an Ioptron CEM70 mount with guiding (+SC -controlled dithering) via PHD and a f = 160mm guide scope with an ASI 120 MM camera.

ASI294MC PRO camera run at -10C and above set up at 0.95 arcsec/ pixel. Bortle 6 skies (no moon)

171 x 40s exposures at gain 124 - Captured in SC and images preprocessed and processed in PixInsight.

(Just to note that he last 2 months I have been using SC4 - 64bit Beta version and that - for my set up anyway - it has proved very reliable and a number of the new features - especially the focusing and image centering- have made it even better to use!)

I used to think it was called 'Iris' as in the iris of a blue eye --- but now that I can make out the dusty petals I suppose it to be an Iris flower?

TimH

Re: NGC7023 Iris nebula

Posted: Tue May 11, 2021 10:00 pm
by oopfan
Up late? I love those dark nebulae!

Re: NGC7023 Iris nebula

Posted: Tue May 11, 2021 10:21 pm
by turfpit
Tim

Good image - I class that as a hard target.

Dave

Re: NGC7023 Iris nebula

Posted: Wed May 12, 2021 8:14 am
by Menno555
Great capture Tim!
The cool bit for this nebula is that there is rather a lot of brown/orange in the dark clouds. It's starting to show in you capture too.

Menno

Re: NGC7023 Iris nebula

Posted: Wed May 12, 2021 10:43 am
by timh
Thanks folks. In case useful I would say that the most critical bit was in the processing and especially in carefully first removing the Bortle6 surburban light gradients. For this I used the PixInsight DBE tool - three successive times in fact - and each time keeping the sampling points mainly within the starry background and away from the thickest bits of dark nebula dust (it is probably faintly everywhere within an image at my scale) . That done well enough then colour calibration and noise reduction steps etc. all went smoothly.
TimH