RandoziDepth of Field Calculator
Enter your lens, aperture and subject distance to see how much of the scene is sharp, where it starts and ends, and the hyperfocal distance.
Total depth of field
58.0 cm
From the near limit to the far limit of acceptable sharpness.
- Near limit
- 2.74 m
- Far limit
- 3.32 m
- Hyperfocal distance
- 30.84 m
Focus at 30.84 m and everything from 15.42 m to infinity is acceptably sharp.
How it works
- Pick your sensor size. It sets the circle of confusion; you can also type your own.
- Enter the focal length in millimetres, the aperture (f-number) and the focus distance in metres.
- Read the near and far limits of sharpness, the total depth of field and the hyperfocal distance.
- Try a smaller aperture or a longer distance to see how the zone of sharpness grows.
What people use it for
Portraits
Check that both eyes stay sharp at f/1.8 or isolate the subject from a busy background.
Landscapes
Focus at the hyperfocal distance so everything from half that distance to infinity is acceptably sharp.
Video and cinema
Plan focus pulls and decide how much margin an actor has before they leave the sharp zone.
Questions
- What formulas are used?
- Hyperfocal distance H = f² ÷ (N × c) + f, where f is the focal length, N the f-number and c the circle of confusion. For a distance s: near limit = s × (H − f) ÷ (H + s − 2f), far limit = s × (H − f) ÷ (H − s). Depth of field is far minus near.
- What is the circle of confusion?
- It is the largest blur spot still seen as a point. This tool uses the sensor diagonal divided by 1500: about 0.029 mm for full frame and 0.019 mm for APS-C. A stricter value, for large prints or pixel peeping, gives a shallower depth of field.
- Why is the far limit infinite?
- When you focus at the hyperfocal distance or beyond, the far limit has no end. Everything from about half the hyperfocal distance to infinity is acceptably sharp.