# Depth-of-field estimate
# Scope: Thin-lens hyperfocal/near/far distances; object inside hyperfocal distance.
# Status: illustrative worked example; engineering review pending.
# Inputs are example values. Checks are editable example requirements, not standards.

focal = 50 mm
fNumber = 8
circle = 0.03 mm
distance = 2000 mm

hyperfocal := focal^2/(fNumber*circle)+focal [mm]
near := hyperfocal*distance/(hyperfocal+distance-focal) [mm]
far := hyperfocal*distance/(hyperfocal-distance+focal) [mm]
depth := far-near [mm]

check finite far limit applicability: distance < hyperfocal

scenario alternative: focal = 40 mm