M27 in a Canon 60Da

Here is  a summer time project made up of data from three imaging sessions. A friend challenged me to see if I could bring out the very faint outer  halo without using filters. It took over three hours of exposure in total, but the halo is there. Click on the image to see a higher resolution view. Click again to return to the original.
Object M27, RA 19:59.6 Dec  22:43
Exposure 209 minutes (69 X 3 minutes)
ISO 1600
Camera Canon 60Da DSLR
Optics 200mm SkyWatcher f/5 Newtonian reflector with Paracorr for a total  focal length of 1150 mm

Marion Bridge, N.S., St. Croix, N.S. and  Smiley's Provincial Park

Processing Calibration and stacking  Images Plus . Masked stretching and split star processed in Images Plus. The masked stretch limits the increase in noise when stretching the image. After the initial stretch the feature mask was used to split the stars from the image and SMI processing was used to further enhance the nebula. Colour enhancement done in LAB colour space using Images Plus 6 beta with curves.  The star colour was enhanced by selectively increasing the red then the blue saturation. Finally the two images were recombined and the background  brightness was set using levels  to adjust the black point.