The Practical Zone System for Film and Digital Photography, 6th Edition

Appendix I The Practical Zone System Film and Developer Testing Method

Many years ago as I was learning the Zone System, I went through the frustrating process of designing home film and developer testing methods that attempted to reproduce the procedures I read about in articles and technical books. This included building handmade densitometers out of wooden index card boxes and setting up lights in my musty basement; none of these approaches were either simple enough or precise enough to teach me what I wanted to know or how all this applied to the photography I wanted to do. Eventually, I learned enough by trial and error to make the system work well, but when I decided to write the first edition of this book, I knew I needed a better solution ...