NGC 6888


object NGC 6888
constellation Cygnus, the swan
equipment ASA Astrograph 10" at f/2,8, SBIG ST-8300M, ASA DDM85 mount
exposure 9x300s H-Alpha, 6x300s OIII, 7x300s B, Baader Filters,no Autoguiding
date 03.08.2011, Engelhardsberg Germany
conditions stars 5m2
image processing DeepSkyStacker 3.3.2, Photoshop CS4, PixInsight 1.6
remarks extreme gradient in sharpness from top to bottom of the picture FWHM from 2" to 5", reason unknown