About image
NGC 1491 is an emission nebula in the Perseus constellation, with dimensions of 9'x6 '.
It 'sa relatively bright object, already visible with poses ccd of a few seconds even in my tele C9.25 HD at f / 10.
Near the nebula extends a whole area of much weaker nebular emission.
The image is a Ha / OIII composition obtained with the Cannistra method (R = Ha, B = OIII, G = Ha + OIII).
This is the first work obtained with the Active Optics of the Starlight Xpress on the glorious Losmandy G11 (a bit in trouble to chase the focal length of C9.25)

Technical data
Optic            Celestron C9.25 Edge HD f/10
Mount          Losmandy G11 with Ovision worm and FS2
Camera           Atik 4000 with Starlight Xpress filter wheel 5 positions
Filters        Baader Ha 7nm and OIII 8.5nm, 50.8 unmounted
Guiding system      SXV-AO-LF with OAG LB Astro Proxima and Lodestar
Exposure details    Ha 25x900" bin1 -20C
                                      OIII 21x900" bin1 -20C
Total integration    11.5h
Acquisition        Maxim, PHD2
Processing        Maxim, Photoshop CS5
SQM-L          18.39    
Location         Home terrace (Rescaldina, Italy)
Date            4/5/27 November 2015