M 31 – Andromeda Galaxy

Date/time: 23.10.2008 21:35 to 24.10.2008 00:20
Az./Alt. positions: 109° / 73° to 244° / 74°
Ambient conditions: 0°C, transparency 4/5, seeing 4/5,
¼ Moon, Moonrise at 02:13
Location: Trier, Germany

Equipment:
Telescope: TMB 92 SS f/5.5 without flattener
Mount: CGE, selfguided with ST-4000XCM  
Camera: SBIG ST-4000XCM

Acquisition:
Software: CCDSoft V5
FOV, Image scale: 102,8 x 102,8 arcmin, 3,01 arcs/pixel
Sub-exposures: 2h 15min (7 x 5min + 10 x 10min) lights at –30°C,
50 x 5min + 50 x 10min darks,

Processing:
Calibration, Min/Max Exc Avg stacking and Add combine
of 5min and 10min stacked frames and DDP in Images Plus 3.0,
Curves and Levels adjustments in CS3,
Noise reduction with Carbonis Actions under CS3,
Non-linear saturation curve in Pixinsight LE 1.0.1

Comments:
This is the first test image with the new TMB 92 SS, our first APO refractor
arrived one day before. Stars are not round in the corners due to the absence of a flattener.
Some light pollution gradient is also present. After struggling with the quite low image
quality of our previous SC scopes, we were quite impressed with the high light
gathering level and image quality of this small refractor.