Jernej LeticaPhotography Tools & Stories
Photography Calculators

Work out how much of a photo is in focus

Enter the sensor, focal length, aperture and subject distance to get the sharp zone, the hyperfocal distance and a diagram. Runs in your browser.

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Sharp zone
Near limit
Far limit

Hyperfocal distance

How to work out depth of field

  1. Choose the sensor format. Full frame is the default; APS-C, Micro Four Thirds and 1-inch use a smaller circle of confusion.
  2. Enter the focal length in millimetres and the aperture as the f-number, such as 2.8 for f/2.8.
  3. Enter the subject distance in metres or feet, or choose focus at the hyperfocal distance to focus at the distance where everything from half of it to infinity is sharp.
  4. Read the near and far limits. The far limit reads Infinity when the subject is at or beyond the hyperfocal distance.

Hyperfocal distance and the sharp zone

The hyperfocal distance is the focus distance at which the far limit reaches infinity. For a full-frame 24 mm lens at f/8 with a circle of confusion of 0.030 mm it is 2.42 m. Focused there, the near limit is 1.21 m, half of that figure, and everything from 1.21 m to infinity is sharp. Focused closer than 2.42 m, the far limit is a finite distance.

Front and back of the subject

The sharp zone is not centred on the subject. On full frame with a 50 mm lens at f/2.8, focused on a subject at 3 m, the zone runs from 2.73 m to 3.33 m: 0.27 m in front of the subject and 0.33 m behind it, a split of 45 % and 55 %. While the subject is beyond the focal length and inside the hyperfocal distance, the part behind it is always the larger share. The split shows that percentage for the distances you enter.

Sensor format and the circle of confusion

The circle of confusion is the blur spot that still looks sharp. It is smaller for smaller sensors, which are enlarged more for the same print: 0.030 mm for full frame, 0.020 mm for APS-C 1.5x, 0.019 mm for APS-C 1.6x, 0.015 mm for Micro Four Thirds and 0.011 mm for 1-inch. At the same focal length, aperture and distance, a smaller circle gives a narrower zone: 50 mm at f/2.8 and 3 m gives 0.60 m with 0.030 mm, 0.40 m with 0.020 mm and 0.30 m with 0.015 mm. At the same framing a crop sensor is deeper, because its lens is shorter: a 33 mm lens on APS-C 1.5x at f/2.8 and 3 m gives 0.94 m, and a 25 mm lens on Micro Four Thirds gives 1.25 m.

On the kit I use

My kit is a Sony A7 III, a full-frame camera, with a 16-35 mm f/4 zoom, a 24 mm f/1.4 GM and an 85 mm f/1.8. With the 24 mm at f/1.4 focused at 2 m, the sharp zone runs from 1.75 m to 2.34 m, which is 0.59 m deep. The 85 mm at f/1.8 focused at 3 m leaves only 0.13 m sharp, from 2.94 m to 3.07 m. The 16 mm at f/4 focused at 2 m runs from 1.04 m to 28.57 m.

Tips for better results

  • Use the distance to the subject you focus on. Lens scales are read from the sensor plane, so a distance measured from the front of the lens is slightly off.
  • Change one setting at a time and watch the diagram: a smaller f-number narrows the zone, a larger one widens it.
  • For a landscape with a far horizon, focus at the hyperfocal distance so the far limit is infinity.
  • The result is the arithmetic of the formula. Check one frame on the camera display before a shoot that depends on it.

Privacy

Your entered content never leaves your device. The calculations and the diagram run locally in your browser.

Frequently asked questions

What is the depth of field calculator formula?

The hyperfocal distance is H = f² / (N × c) + f, with f the focal length, N the f-number and c the circle of confusion, all in millimetres. Focused at a distance s, the near limit is s × (H − f) / (H + s − 2f) and the far limit is s × (H − f) / (H − s). The far limit is infinity when s reaches H.

What is the hyperfocal distance formula?

H = f² / (N × c) + f. A full-frame 24 mm lens at f/8 with c = 0.030 mm gives H = 2.42 m. Focused at that distance, everything from 1.21 m to infinity is sharp.

Does a smaller sensor have more depth of field?

Not at the same focal length, aperture and distance: its circle of confusion is smaller, so the zone is narrower. A 50 mm lens at f/2.8 and 3 m gives 0.60 m on full frame and 0.40 m with 0.020 mm. At the same framing it is deeper, because the lens is shorter: a 33 mm lens on APS-C 1.5x at f/2.8 and 3 m gives 0.94 m.

What circle of confusion should I use?

Use the value for your sensor format: 0.030 mm for full frame, 0.020 mm for APS-C 1.5x, 0.019 mm for APS-C 1.6x, 0.015 mm for Micro Four Thirds and 0.011 mm for 1-inch. The custom option takes any value if your print size or viewing distance differs.

Why does the far limit say Infinity?

Once the subject is at or beyond the hyperfocal distance, the formula has no finite far limit. Everything behind the subject is acceptably sharp out to infinity.

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