M22 (NGC 6656) is a very nice mag 5.1 globular cluster that is just a little bit to the east of the top star of the tea pot asterism in Sagittarius. M22 is a gravitationally bound group of stars and contains about 500 hundred thousand stars. It has been hot here in central Arizona and in our monsoon season but we have not had all the clouds we usually do, so I decided to go out to the observatory and take this photograph. I also tried something new for me; I took dark-flats as one of the calibration images to help reduce noise and it seems to have helped. This from my very light polluted sky (Bortle 8-9).
Photographer: Rick Scott
Date / Time: August 6, 2020 from 8:36 to 9:45 PM MST
Telescope: home-made 10" f/4.6 Lurie-Houghton
Mount: Losmandy HGM Titan with Gemini 2
Guiding: ZWO 60280, ZWO ASI120MM Mini, PHD2
Camera: Canon EOS 60Da controlled with BackyardEOS
Filter: Optolong L-Pro
Exposure 29 x 60 sec, f/4.6, ISO 400 in raw mode
40 flats, 40 bias, 40 darks, and 40 dark-flats
Processed in Deep Sky Stacker (DSS) and Adobe Photoshop CS6.
Updated: August 7, 2020