As of today it should be easy to do a relatively cheap rapatronic-like camera with LCD film.
The basic principle is more or less the same: two linearly (?) polarized sheets at 90° that block all the light going through, and a sheet/material in the middle that rotates 90° the light polarization when an electric current is applied. Some of those glass windows that can obscure instantly work with this technology. https://en.m.wikipedia.org/wiki/Liquid-crystal_display
What I don't know is the speed of polarization rotation for liquid crystals (compared to a Kerr cell) that would define the minimum "obturation" speed available.
See https://www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=81... for examples of modern LCD shutters. They have closing times that are in the hundreds of microseconds, so they are not really replacements for ultra-short exposures. But they are "cheap".
That seems to match with a shutter vendor that says "50 microsecond rise time 1.3 millisecond fall time". So I guess 'rising' is going dark, and 'falling' is going clear.
Or 'rising' means changing the natural state of the crystal (thus rotating 90° the polarization), and 'falling'... well, falling back to the natural resting state. It makes some sense that falling back when unenergized is slower than rising.
Now it'd be interesting to know what happens during rise and fall time. Progressive linear polarization? Waiting time until the crystal reacts?
The basic principle is more or less the same: two linearly (?) polarized sheets at 90° that block all the light going through, and a sheet/material in the middle that rotates 90° the light polarization when an electric current is applied. Some of those glass windows that can obscure instantly work with this technology. https://en.m.wikipedia.org/wiki/Liquid-crystal_display
What I don't know is the speed of polarization rotation for liquid crystals (compared to a Kerr cell) that would define the minimum "obturation" speed available.