Depth of Field Calculator
Total Depth of Field
Hyperfocal Distance
Near Limit
Far Limit
Total DoF
Hyperfocal Distance
Near Limit
Far Limit
Total DoF
Depth of field (DoF) is the distance between the nearest and farthest objects in a scene that appear acceptably sharp in a photograph. A camera lens can only focus precisely on one plane, but there is a range around that plane where objects still look sharp to the human eye.
This apparent sharpness is defined by the circle of confusion (CoC) — the maximum size of a blur spot that still looks like a point to a viewer. Canon uses specific CoC constants for each sensor format: 0.030 mm for full-frame, 0.019 mm for APS-C, and 0.023 mm for APS-H sensors.
Three factors control depth of field: aperture (wider apertures like f/1.8 produce shallower DoF), focal length (longer lenses compress DoF), and subject distance (closer subjects have thinner DoF). The hyperfocal distance is the focus distance that maximizes DoF — everything from half the hyperfocal distance to infinity will appear sharp.
You're shooting a portrait with an 85mm lens at f/1.8 on a full-frame camera. Your subject is standing 8 feet (about 2.4 meters) away.
Focal Length = 85 mm
Aperture = f/1.8
Subject Distance = 8 ft (2,438 mm)
Sensor = Full Frame (CoC = 0.030 mm)
Hyperfocal Distance = 134,028 mm ≈ 440 ft
Near Limit ≈ 7.85 ft
Far Limit ≈ 8.15 ft
Total DoF ≈ 0.30 ft (3.6 inches)
With only about 3.6 inches of depth of field, you need precise focus on your subject's eyes. This razor-thin DoF is what creates the creamy background blur (bokeh) that portrait photographers love.
The circle of confusion (CoC) is the largest blur spot on a camera sensor that still appears as a sharp point to the human eye when the image is printed or displayed at normal viewing distance. It depends on sensor size — smaller sensors use a smaller CoC threshold because the image must be magnified more to reach the same print size.
A wider aperture (lower f-number like f/1.8) produces a shallower depth of field, isolating the subject from the background. A narrower aperture (higher f-number like f/16) produces a deeper depth of field, keeping more of the scene in focus. However, extremely small apertures (f/22 and beyond) can reduce overall sharpness due to diffraction.
The hyperfocal distance is the closest focus distance at which objects at infinity still appear acceptably sharp. When you focus at the hyperfocal distance, everything from half that distance to infinity falls within the depth of field. Landscape photographers use this technique to maximize sharpness throughout an entire scene.
Yes. A larger sensor (full-frame) produces shallower depth of field than a smaller sensor (APS-C) at the same focal length, aperture, and framing. This is because the larger sensor uses a larger CoC threshold and requires a longer focal length or closer distance to achieve the same framing, both of which reduce DoF.
Yes. When the subject is focused at or beyond the hyperfocal distance, the far limit of the depth of field extends to infinity. This means everything from the near limit to the horizon will appear sharp. This is common in landscape photography with wide-angle lenses at narrow apertures.