Diffraction spike generator for Nikon 200-500 f5.6 lens hood

I designed this part to create the diffraction spikes seen in images taken through reflector telescopes, with the main goal of concealing any small focus errors.

It fits the Nikon HB-71 lens hood found on the Nikon 200-500mm f5.6. I'm not sure what other lenses came with this hood, or what other lens hoods it may fit. It could probably be scaled to fit other lenses and might need to be sanded down slightly to get a good fit.

The attached images are samples I took with this tool installed on my camera. The last image shows what photos look like without it installed for comparison.