Solar Eclipse Filter for Canon EF 24-70mm F2.8 L USM ZOOM lens

This solar filter body has an ID (inner diameter) of 84mm so it fits nicely over the end of the lens with just a little play. For reference, 84mm is about 3.25 inches in diameter.
I printed the pieces separately to eliminate stringing between parts.

You will need the actual solar film to construct this, as the 3D printed parts are only the frame. I used Thousand Oaks Optical silver black polymer film.
https://thousandoaksoptical.com/shop/solar-filters/silver-black-polymer-sheets/

This is a threaded design and the solar film is held in place by pinching it in between the body and cap.  They are threaded with a ultra-fine thread.  This thread can be frustrating with 3D printed parts, but some patience is useful. Use a 0.4mm nozzle and very fine layer height for the threaded feature (0.07mm - 0.10mm layer height). I used variable height printing in PrusaSlicer, with the threaded region set at 0.07mm and 0.2mm above the threads. I used PLA+ for these and had good luck with the fine threads.  Work the threads in by twisting back and forth and then cleaning any plastic debris/dust and the then the threads should be relatively smooth. I scaled the solar film template disc to 84mm.  Use an X-acto knife to cut around it.  Finally, assemble the filter with the film.