The images below show the results of unsharp masking applied
to the original image. On the left the original image is
shown with, in general, an over-illuminated central part.
Applying an unsharp masking algorithm (consisting of sub-
tracting a smoothed image from the original) yields the
image on the right.
All images: CCD: FT800 CCD in prime focus
Scope: 25cm f/D=5.8 Newton
Date: May 1998
Illum.: M63 sum of 11 images of 90 seconds
M94 sum of 9 images of 60 seconds
M106 sum of 11 images of 90 seconds