Depth of Field Calculator

Through the circle of confusion and the framing chain: a smaller sensor's image is enlarged more for the same print, so its acceptable blur circle is proportionally smaller (0.030 mm full-frame vs 0.015 mm Micro 4/3) — but to frame the same shot it also uses a shorter focal length, and that effect dominates. Net result at equal framing and f-stop: a 2× crop sensor gives about two stops MORE depth of field. That's why phones fake bokeh computationally and large formats melt backgrounds effortlessly.

Only near one specific distance: DoF is split roughly 1/3 front, 2/3 behind at moderate portrait distances, but it approaches 50/50 in macro range and runs to all-the-way-to-infinity behind once you focus past hyperfocal. The rule is a snapshot of a continuously varying ratio — this calculator's near/far outputs show the real split at your settings, which is more reliable than the folklore.

Different quantities: DoF measures the sharp zone around the subject; background blur measures how large a far-away point renders, and it scales with physical aperture diameter (focal length ÷ f-number) and subject-to-background separation. A 200mm f/4 (50mm pupil) blurs a distant background more than a 50mm f/1.8 (28mm pupil) despite similar DoF numbers. For creamy backgrounds: longer lens, closer subject, distant background — then aperture.

Hyperfocal focusing (focus AT H, sharp from H/2 to ∞) maximizes the zone but puts infinity at the very EDGE of acceptable sharpness — distant mountains render at the blur threshold, visibly soft on large prints. Working practice: focus at 1.5–2× the hyperfocal distance, or focus on the horizon when distant detail is the subject and let the foreground fend for itself. The calculator's H value is the reference point; doubling it is the safety margin.