Here is a recent reprocessing effort on some data collected last year. M51 is a favorite galaxy of many imagers as it contains prominent spiral arms. This image was taken without a coma corrector so the stars at the corners are slightly elongated. 

Click on the image to see my original attempt at processing this image, click again to return to the initial image.

Object M51 RA 13:29.9 Dec +47:12
Exposure 60 minutes (12 X 5 minutes)
ISO 1600
Camera Canon 350D DSLR
Optics 8" f/4 Schmidt Newtonian Telescope

St. Croix Observatory

Processing The processing starts with calibration an stacking using Images Plus. Next the background was equalized in Images Plus then two images were saved with different stretches using the digital development function. Paint Shop Pro was used to combine both images using a LMS technique. Masked noise reduction was applied to the deep sky layer to reduce the noise. The remaining gradient was corrected using a layered technique in Paint Shop Pro. The combination of noise reduction and gradient removal left some minor blotches in the background. These were removed using Paint Shop Pro and the star colour enhanced. Finally the image was transferred back to Images Plus for a deconvolution run to sharpen the image a bit and a star reduction run to get rid of some minor star bloat that occurred during the stretch operation.