Updated on November 3rd, 2014

Photos of open star clusters always appear to be more pleasant when stars have diffraction spikes.  But if your telescope does not have support vanes from a secondary mirror you are out of luck.  One solution is to simply tape in a cross pattern some string or fishing line over the dew shield.  Or you can turn to digital enhancement.  Below is a procedure to enhance your photos by digitally adding diffraction spikes using GIMP 2.8. in 8 easy steps!  No special plugin or filter required.

Lets try with my image of M45 – Pleiades taken with a Skywatcher 80ED.

M45 – Pleiades
Benoit Guertin

The first step is to create a new “brush” in the shape of diffraction spikes.  To do this, start with new canvas with a transparent background.  In the screen shot below, a new 1000 x 1000 pixel image with Fill with: Transparency