M 27 - Dumbell Nebula

Date/time: 14.10.2007 21:07 to 14.10.2007 21:46
Ambient conditions: 10°C, transparency 4/5, seeing 4/5
Location: Trier, Germany

Equipment:
Telescope: Celestron SC 8” with focal reducer f/6.3
Mount: CGE unguided
Camera: NIKON D-40X unmodified

Acquisition:
Images Plus Camera Control 3.0
FOV, Image scale: 42.8 x 63.9 arcmin, 0.98 arcs/pixel
Sub-exposures: 34min (7 x 2min + 4 x 5min) lights at ISO 800, 4 x 2min + 4 x 5min darks

Processing:
Calibration, Min/Max Exc Avg stacking and Add combine of 2min and 5min
stacked frames in Images Plus 3.0. Curves and Levels adjustments, digital flat subtract,
highlights enhance, color correction and sharpening in CS2. Noise reduction with
Noiseware Community Edition

Comments:
This is my first image acquired through the SC 8” using the unmoded D-40X.
Considerable vignetting was produced by the focal reducer. Oval stars throughout the field
is due to tracking errors and to not collimated scope. The processing technique was
mainly based on the book A Guide to Astrophotography by Jerry Londriguss.