I have restricted most of my LF phtots so far to color because of the mediocore or expensive results I've had from commercial B+W processing/printing. I'd like to while away a few cold evenings reading more about the zone system and process ing/developing. There are certainly some basics on the web but I'm looking for a little more. Any recommendations. Considering - The Negative, Beyond the Zon e System, The Practical Zone System. Can't afford them all. Recommendations ap preciated.