TL;DR: this is an approach that simplifies the production of light field cameras (cameras that measure both color and angle of incoming light beams): instead of building a grid of microscopic lenses, you use a "random" piece of opaque plastic like scotch tape, and figure out how it modifies incoming light using a calibration phase.
Here is a similar approach using water droplets instead of a diffuse film, but they don't go as far as performing 3D reconstruction from the light field and the ray directions are not calibrated by a calibration pattern but by inferring a 3D model of the droplets: https://light.cs.uni-bonn.de/4d-imaging-through-spray-on-opt...
Could some middle-ground device exist where the lens is still manufactured for this use-case but still lower cost overall as the system has a high tolerance for quality/defects by implementing the calibration step?
Sounds reasonable. They basically proved that the worse possible lens they can manufacture can still provide the information they need. I have no idea what the size of the relative trade offs involved are - ie, if you loosen the tolerance of your lens manufacturing by X%, what increase in computation is required. Exciting times!
