Reflection nebula "Iris" (Iris Nebula) NGC 7023, Caldwell 4

Reflection nebula "Iris" (Iris Nebula) NGC 7023, Caldwell 4
A large gas-dust cloud of complex composition.
In the center is a binary system of young Herbig Ae/Be stars.

Equipment:
Camera Canon EOS 200 Da.
Telescope Synta SkyWatcher 150/750, F/5
Mount HEQ-5 Pro
Bahtinov mask
Polar finder camera iOptron iPolar
Coma corrector Baader MPCC Mark III
Guidescope SVBONY 60/240, F/4
Guide camera ZWO ASI 120 Mini
Flat panel Gemini 190 mm

Capture software:
Astrophotography Tool, SharpCap (polar alignment), EQ-Mode, ASCOM, Cartes Du Ciel, PHD2

Suburb of Chelyabinsk, Kremenkul area.
Red light pollution zone. Class 7 on the Bortle scale.

Capture 05-06.05.2026
Total 109 light frames of 90 seconds each + 20 dark frames + 20 bias frames + 20 flat frames
ISO 800

Capture 06-07.05.2026
Total 104 light frames of 90 seconds each + 20 dark frames + 20 bias frames + 20 flat frames
ISO 800

Total integration time Σ=5h19'30"

Post-processing software:
DeepSkyStacker, FitsWork, FITStacker, Lightroom, StraNet2GUI, Photoshop, Topaz Denoise AI