For B&W, in BTZS, you take two readings, one where you "simulate" shaded part of your subject (to guess the amount of light "incident" under the tree for example). Then you take a reading in the sun. You use the difference in readings to estimate the subject luminance range, which you then use to decide development.
Originally Posted by baachitraka
The BTZS book explains how to simulate shadow lighting effectively without carrying it too far. So it would be worth picking up if you plan to use this method. Then you won't have to rely on distorted translations (which this is probably a good example).