Depth of Field: Two Subjects

Say what has to be sharp. Most of these tools ask for one distance and hand back a range. Real frames have two things in them — the rock in the foreground and the ridge behind it, the front petal and the back of the flower. Give this one both distances and it works the other way round: where to focus, and which apertures actually reach from one to the other. The exact requirement, not the nearest stop. If a frame needs f/9.6, that is what it says, along with the first stop on the ladder that satisfies it and the one below that does not. Thirds of a stop are on the ladder, so a value the whole stops skip over is still yours to use. No model list to be missing from. Twenty-four formats, from sheet film down to a phone. Choose a sensor by its measurements, or type the two numbers off the maker's spec sheet. There are no brands and no models anywhere in this app, so the table cannot go out…