The polarizer and phototransistor taped to the iPhone. [Dave] wrote to tip us off about [Paul Wallace]’s take on the same idea, a DOLPi-inspired polarimetric camera using an iPhone with an ...

(Polarizing filters can also be used to darken ... using a black cloth the way we did in in our Reflections in Photography video. And if you need to photograph (or film) a really large storefront ...