Customizable Diffraction Mask

I created this customizable mask to add star-spikes to my William Optics Z73 doublet telescope, but I built it using OpenSCAD so that it could be customized for any telescope. You can also customize the width of the "supports" that produce the spikes.

Star diffraction spikes are produced because the image of a point source light at "infinity" through a telescope will be the 2D Fourier Transform of the shape of your aperture (with additional aberration and distortion produced by the optical train itself). I recommend printing this without a raft so that the supports are as sharp of a transition as possible. Sharper transitions have higher spatial frequency components, which means that the spikes will extend further out from your stars. The width of the spikes will change the spread of the spikes near the star itself. Making the supports thinner will make the spikes extend further, but they will be less bright overall. Making them thicker will make them brighter near the star, but make them shorter. More info on the derivation of these properties can be found here.

These are pretty fast to print, so I recommend trying a few settings and experimenting with some different masks to see what star spikes you like on your images.