NGC 281 (the Pacman nebula), an emission nebula in Cassiopeia. Image shown at 66% of size
Equipment: VixenVC200L scope. ASA DDM85 mount. SBIG STL11000 camera. H alpha, Red, Green and Blue filters
Location: Pozuelo home observatory (Madrid suburbs)
Date: October and November 2011
Exposure: 12x60 minutes H alpha, 10x15 minutes Blue, 8x15 minutes green and 8x15 minutes red. Total exposure: 18 hours and 30 minutes.
The H alpha channel was employed as luminance and to"lighten" the RGB color channels (Red 100%, Blue 15% and Green 5%)
Light pollution gradients in the RGB channels (Madrid center at 10 Km!) were corrected with the DBE function (dynamic background extraction) in Pixinsight.