Marc Levoy's Lectures on Digital Photograph

If you want to learn about photography, Marc Levoy's lectures are some of the best content I've seen. For the mildly experienced photographer (like myself) with an engineering background, his explanations fill in so many gaps with mathematics and physics.
Topics like:
- how do lenses work and what are the limitations?
- how does perspective and depth of field work?
- the history of photography
- and much more
He's a big deal in the field of digital photography, especially with HDR: https://en.wikipedia.org/wiki/Marc_Levoy
There are 18 lectures, and they're all excellent.
Youtube Playlist: https://www.youtube.com/watch?v=y7HrM-fk_Rc&list=PL7ddpXYvFXspUN0N-gObF1GXoCA-DA-7i