If you are interested in the Zone System, I wouldn't recommend taking advice from a site that gives 10 reasons not to use the Zone System.
Originally Posted by MatthewDunn
If you develop by time and temperature to manufacturer's recommendation, you MIGHT get rated box speed, and you MIGHT get a Contrast Index of 0.62. That's what I believe these charts aim to lead you to. You will get negatives you can print. But you will miss out on some of the understanding that comes when you test for film speed and development time.
If you develop tests of Stouffer scale step wedges and read the results with a densitometer, and you make your own Time-CI chart and family of curves. You will know what speed you are getting and you can plan the development to fit your needs.
Going forward if you include a step wedge exposure in with your normal developing runs, you will know whether you hit your predicted CI and can adjust processing or update your charts as needed.
That's the approach I would recommend if you were to consult me, and like #10 of Roger and Frances, I'm sticking with that. Haa, no. If you want to discuss any other approach, I'm always willing to explore the strategy and pros and cons...