Although this book is not for everyone, I found it to be the best explanation and reference for many aspects of photography. Unlike other books, this goes into depth to explain the technology well. It is the kind of book that explains Density vs. Exposure curves, color balance and white point temperature (even mireds), lens, cameras, studio lights, etc, etc. It doesn't go into great depth of how to actually compose and capture a great picture, but it does go a long way to explaining how the tools work at a level that engineers or technology-savy people will appreciate.