“An interactive deep-dive into how cameras and lenses actually form images, with simulations you can manipulate in your browser.”
Ciechanowski makes the most thoughtful technical explainers on the open web. Every piece is a multi-month project, every piece is free, and every piece is the kind of work that justifies the existence of the medium. The cameras and lenses post is six years old and still better than any textbook chapter on the subject. Bookmark the whole site.