Samyang 135 mm diffraction spikes

thingiverse

This is a (very basic) model to add diffraction spikes to a Samyang 135 mm f/2 lens. What are diffraction spikes? Those are the typical cross-shaped spikes one can see around (radiating from) bright sources. Typical are stars on astronomy photographs. They are typical of newtonian telescopes, or any telescope having a "spider" as secondary mirror holder. They are therefore absent of refractors, lenses most of cassegrin telescopes (Schmidt, Muksutov, ...). They might have become in the imaginary of what an astronomy picture looks like thanks to the HST and JWST. Weather they are desirable or not is totally up to you ;-) This is an artistic opinion and there is no good or bad answer. Than can also be useful for focusing a lens, though a Bahtinov mask is probably way more useful. This design is only the "holder" for diffraction spikes, as printed spikes would probably be too fragile. The design has 4 notches at 90° where you can insert anything. I used old guitar strings. Slightly heated so they'd melt into the PLA and secured with a drop of cyanoacrylate. Note: keep cyanoacrylate away from lenses as it outgasses for a while!