Depth of field
calculator.
Set your format, lens and stop, and see exactly where focus falls off — near limit, far limit, total depth of field and the hyperfocal distance. For directors of photography, ACs and stills shooters.
Uses the standard circle of confusion for the chosen format. "Acceptably sharp" depends on viewing size — treat it as a reliable guide, not a guarantee.
These calculators live in the apps, too.
Set Math puts depth of field and fifteen more camera calculators in your pocket, free. DOPro adds a real director's viewfinder with lens presets, so you can see the frame and the focus falloff on set.
Four things set the focus zone.
Change any one and the sharp zone grows or shrinks. The calculator does the arithmetic; this is the intuition behind it.
Aperture
Stopping down (higher ƒ-number) deepens the focus zone; opening up throws more out of focus. The biggest, fastest lever you have.
Focal length
Longer lenses render a shallower zone at the same framing; wider lenses hold more in focus.
Subject distance
The closer you focus, the thinner the sharp zone. Depth grows quickly as the subject moves away.
Format & circle of confusion
Bigger sensors tolerate a larger blur spot, which shifts the numbers. That's why the format picker matters.
How to calculate depth of field
The calculator uses the standard thin-lens formulas. Work in millimetres throughout, with f the focal length, N the ƒ-number, c the circle of confusion for your format and s the distance you focus at.
- Hyperfocal distance:
H = f² ÷ (N × c) + f - Near limit:
Dn = H × s ÷ (H + (s − f)) - Far limit:
Df = H × s ÷ (H − (s − f))— if s is at or beyond H, the far limit is infinity. - Depth of field:
DoF = Df − Dn
The circle of confusion is the largest blur spot that still reads as sharp. Common values: 0.030 mm for full frame, 0.020 mm for Super 35 and APS-C, 0.015 mm for Micro Four Thirds and 0.011 mm for Super 16.
Worked example
A 50 mm lens on Super 35 (c = 0.020 mm) at ƒ/2.8, focused on an actor 3 m away:
H = 50² ÷ (2.8 × 0.020) + 50 ≈ 44,693 mm, about 44.7 m.Dn = 44,693 × 3,000 ÷ (44,693 + 2,950) ≈ 2,814 mmDf = 44,693 × 3,000 ÷ (44,693 − 2,950) ≈ 3,212 mmDoF ≈ 3,212 − 2,814 = 398 mm
So about 40 cm is acceptably sharp: roughly 19 cm in front of the actor and 21 cm behind. Stop down to ƒ/5.6 and the zone roughly doubles, to about 81 cm — which is why focus pullers ask for the stop before they mark the floor. Enter the same numbers above to check.
Depth of field, answered.
How is depth of field calculated?
From focal length, aperture, subject distance and the circle of confusion for your
format. The hyperfocal distance is focal² / (aperture × circle of confusion) +
focal; the near and far limits come from that and the subject distance, and depth
of field is the gap between them.
What is the circle of confusion?
The largest blur spot that still reads as sharp for a format. Roughly 0.030 mm for full frame, 0.020 mm for Super 35 and APS-C, 0.015 mm for Micro Four Thirds. Larger formats tolerate a larger spot, which changes the result.
What is hyperfocal distance?
The focus distance at which everything from half that distance to infinity is acceptably sharp — the setting that maximises depth of field for a given lens and stop.