the Negative by Ansel Adams
The second book of Ansel Adams is a handbook on his black and white zone system for optimal film exposure and development. A read for any kind of photographer (both analog and digital) to learn on light with a high technical and systematic approach. Find more info on the book here: https://www.goodreads.com/book/show/20502.The_Negative or
download the PDF: http://www.timlaytonfineart.com/thenegative-ansel-adams.pdf