> Also, I've just read two of Ansel Adams books on the Zone System and would > like to talk - off line - to anyone who can help me extrapolate this to > the pictures that I take. Specifically, I'd like to: > > 1. scan a photograph or negative into my computer (not a problem) > 2. convert the RGB values to % gray (I do not understand how to do this.) You can convert it to gray levels in most paint software. > 3. convert the % gray to zones (I think I understand how to do this, but > I'd like some confirmation.) You should posterize the picture to 10 gray levels. Not sure if the latter is possible (usually, you have to give the number of bits: 4 bits give 16 levels...) > 4. print out the pictures in zones of gray for further study. (Not sure > that monitor RGB and printer density relate to %gray in the same manner.) Well, the zones cover a ten stop range going from pure black to pure white (in theory). This is supposed to be the range b&w films cover. Modern films and colour negatives may have a wider range even. The problem is that scanners, screens and printers all limit the usable range. Consequently, it is difficult to use the zone system in a scientific way with a system you do not master. What would you like to do, in fact? Nicolas
