AMATEUR ASTRONOMY SITE
Javier Gómez Laina                                                                              Sh2-188 in Cassiopeia
Object  Sh2-188         -  emission nebula  -     It is really a very diffuse planetary nebula;  you can see it as a full circle by an extreme image streching.
Telescope Celestron C-8 203mm  f3.0     90mm Guide telescope & QuickCam.
CCD  Starlight MX716 camera. Astronomik  Ha & RGB filters.
Exposures
L
R
G
B
300' Ha  29' 34' 57'
Processing Flats, Darks & Bias calibration, aligning in AIPWin. 
Sigma rejection combining with Ray Gralak's Sigma-Clip.
Deconvolution in AstroArt with Chris' Smart Star Bloat  plug-in. 
PhotoShop: L & R images blended at 80 - 20% for L & R channels.
L (50% opacity) and RGB layers,  gaussian blur and color saturation.
Final image:  LLRGB layers.

This image has appeared on Sky & Telescope Gallery (April/04)