the lab

Depth

where sharpness begins and ends

Depth of field is the viewfinder's oldest bargain: the aperture buys a slice of the world in focus, the slice deepens with distance, and at the hyperfocal its far edge touches the horizon. This page only measures the slice — with the classic forgiving blur circle of diagonal ÷ 1500; your lens, and your print size, are allowed their own opinions. For the slow end of the light there is reciprocity, and for the light itself, the light almanac.

free, no accounts, always — if it earns a place in your day, you can buy me a coffee.