About image
Sh2-140 is an emission nebula in the Cepheus constellation.
The image is my first attempt at mixing Ha and RGB.
The initial idea was in fact to make a bicolor combination HaOIII with frames taken all from the terrace of the house with strong light pollution: unfortunately after obtaining some frames in OIII I realized that there is virtually no OIII signal in this area!
Since the image only in Ha was not very "catchy", I then decided to opt for a Ha-RGB, with the RGB taken from a hill place with dark sky
Technical data
Optic Tecnosky Apo Refractor 115 - 800mm f/6.9
Mount Losmandy G11 with Ovision worm and FS2
Camera Atik 4000 with Starlight Xpress filter wheel 5 positions
Filters Baader Ha 7nm and RGB, 50.8 unmounted
Guiding system TSOAG 9mm with Lodestar
Exposure details Ha 21x900" bin1 -15C
R 5x420" bin2 -15C
G 5x420" bin2 -15C
B 5x420" bin2 -15C
Total integration 7h
Acquisition Maxim, PHD2
Processing Maxim, Photoshop CS5
SQM-L 20.65
Location Pian dell'Armà (Pavia, Italy) for RGB, home terrace (Rescaldina, Italy) for Ha
Date 2 September 2014, 18 July 2015