Skylight

I've been working on sky polarization this week - the sky is blue, but also highly polarized. It's got an interesting pattern on the sky - maximum polarization 90 degrees off the sun.

Here's a bunch of polarization measurements from a paper by Pomozi in 2001. Essentially he used a fish-eye camera with a polarizer on it. The dot is the sun. Left to right it goes clear color picture, polarization, direction, simple model polarization, model direction, cloudy picture, cloudy polarization, cloudy direction.

and here's a simple one - at sunset, dark=polarized.