Some times, especially when on trips of several weeks or more where equipment and materials have to be packed carefully, I use a simple method where I just take an incident meter in the shadow areas where I expect to see texture and detail and follow that up with two-bath development.

With this method you just forgot about all the mumbo-jumbo about how to determine film speed and rate the film at 1/2 the speed recommended by the film maker. The most important issue in determining film speed, as Ken Lee mentioned, is not the way you develop it, but how you use your meter. If you take an incident metering in the shadows, and your meter is calibrated. you will always have sufficient shadow detail. And two-bath development will always limit contrast in the highlights so for scanning this method is pretty much fool proof .

On the other hand, I learned both ZS and BTZS and I still use in many cases the full precision of BTZS in film testing, exposure and SBR determination in the field, and development. I don't however, use any kind of PDA or computer in the field as I find this distracting and the calculations for exposure and SBR are relatively easys to make.

It is obviously not necessary to understand and use ZS or BTZS, or any system for that matter, to make good photographs. But understanding theses systems will enhance your knowledge of the creative controls possible with photographic materials. And once learned, even if you don't use ZS or BTZS in practical work the knowledge will still be in your head and it may be useful in the future.I found this always to be true of the use of LF cameras. The care in composition required by the use of these cameras has come in very handy in my composing skills with MF equipment.

IS BTZS difficult to learn? No, really not at all. The book may be difficult to wade through on your own but anyone with a good understanding of the system could teach you practical BTZS in an afternoon.

Sandy