ExposureMath
Engineering Analysis

Depth of field: the three levers and the one that matters most

Distance is the sleeper lever

Halving subject distance quarters depth of field — a stronger effect than any aperture jump. Portrait photographers "step back and zoom" for exactly this reason: same framing, more working depth. The calculator shows the distance effect explicitly; the muscle memory comes from using it.

Hyperfocal in practice

Focus at H and accept sharp from H/2 to infinity — the maximum sharp zone for any aperture. In the field: compute H once per lens/aperture combo, tape the distance, and landscapes stop being focus lottery. Combined with f/8 (past diffraction's f/16 cliff), it is the entire landscape focus strategy.

Diffraction: the far cliff

Past ~f/11 (full frame), light bends at the aperture blade and softens EVERYTHING — the DoF gains reverse into global blur. The "f/22 for landscapes" folklore walks off that cliff. Hyperfocal at f/8 outperforms everywhere-sharp-at-f/16 on any modern sensor; the calculator's hyperfocal line is the proof of concept.

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