a textbook by Philip Greenspun; revised January 2007
Most photography books start out talking about the various kinds of cameras that are available. Then they talk about lenses, film, and exposure. Only at the very end do they talk about light. This is strange because most people who take good photos seem to start by pulling together light, subjects, and composition. After that is all figured out, then the rummaging through the equipment cabinet to pull out the right camera and lens begins.
This is a photography textbook designed to reflect the way that good photographers think about taking pictures.
Is this the best textbook for beginning photographers? Certainly not. There are many excellent ones on paper, a few of which are reviewed in the book review section. However, if you like this way of thinking about photographs and you don't have a paper book in front of you, this online book might be useful.