M51 Supernova

This is a continuing experiment in urban imaging taken from mag 3 skies. The ISO was reduced to extend the exposure of each sub-frame to four minutes. The conditions were not the best, city light pollution and a bright Moon contributed to limit the visibility to thrid magnitude or brighter stars.

Object	M51 Object RA 13:42.2 Dec +28:23
Exposure	52 minutes (13 X 4 minutes)
ISO	400 (This image was made from urban skies where third magnitude stars were barely visible. Lower ISO was used to increase the sub-exposure integration time)
Camera	Canon 350D DSLR
Optics	8" f/4 Schmidt Newtonian Telescope
Location	Bedford, Nova Scotia
Processing	Calibration, stacking, background noise reduction done with Images Plus . Images Plus digital development function was used for initial stretching. The background was corrected in Paint Shop Pro using a subtractive layer background correction . A masked noise reduction was applied to reduce the background noise further and the resulting low frequency noise blobs were removed using a layered blob removal technique. Star shrink processing was used to slightly reduce the star sizes. The image was reduced in size for this web page then sharpened using Focus Magic.Finally a slight curve stretch was applied in Paint Shop Pro .