A new find for me. Just red channel

Object ID PK205+14.1 / Abell 21 / Sharpless 2-274 Medusa nebula
Gemini
Details 2019-02-26
Telescope 250mm f4.8 Newtonian
IDAS P2 filter
Camera Atik 460EX, Baader RGB
Exposure(s) 10 x 180s Red filter
darks
Capture APT
Processing Nebulosity, Photoshop