About image
The M66 spiral galaxy in the constellation of Leo is a well-known object as it is part of the famous "Leo Triplet" along with M65 and NGC 3628.
M66 is a galaxy with apparent dimensions of 9.1 'x 4.2' and a distance estimated at 35 million light years: its spiral structure is asymmetric and presents considerable amounts of dust.
The RGB was obtained in December 2015 by the dark skies of Aosta Valley (Italy): I was hoping to get even the luminance from the mountain, but I no longer had the chance.
To avoid leaving the shot in half for too long, I decided to take advantage of three clear evenings from home in March 2017 to make the luminance with the IDAS filter.
Obviously this luminance was not up to the color because of the gradients on the sky background and above all the considerable noise on each frame: working a bit up in Pixinsight I managed to get what I think is a good compromise.

Technical data
Optic            Celestron C9.25 Edge HD f/10
Mount          10Micron GM1000 HPS, Losmandy G11 with Ovision worm and FS2
Camera           Atik 4000 with Starlight Xpress filter wheel 5 positions
Filters        Hutech Idas LPS-P2 50.8 unmounted for L, Baader 50.8 unmounted for RGB
Guiding system      OAG Starlight Xpress with Lodestar
Exposure details    L 28x600" bin1 -20C
            R 9x420" bin2 -20C
            G 9x420" bin2 -20C
            B 9x420" bin2 -20C
Total integration    7.8h
Acquisition        Maxim, PHD2
Processing        Pixinsight 1.8, Photoshop CS5
SQM-L         18.5 for L, 21.25 for RGB    
Location         Home terrace (Rescaldina, Italy) for L, Porliod (Aosta Valley, Italy) for RGB
Date             27/28/29 March 2017 for L,19 December 2015 for RGB