If anyone wants to play with a (probably much simpler) blender model of a lens, here's a link: https://studio.blender.org/blog/camera-lenses-with-caustics/ http

If anyone wants to play with a (probably much simpler) blender model of a lens, here's a link: https://studio.blender.org/blog/camera-lenses-with-caustics/ https://studio.blender.org/blog/camera-lenses-with-caustics/ What I've personally always wondered is if you could make a liquid crystal or electrochromatic diaphragm to get perfectly circular bokeh (or maybe even smooth-edge STF bokeh) on demand. Would probably kill the T-stop value when full open due to less than perfect transmissivity though.. I also wonder what would happen if you could substitute an angle-limited piece of glass (kind of like a privacy screen - visible head-on but opaque from an angle) instead of the diaphragm.