Depth of Field Calculator

1. Enter your lens focal length in millimetres.
2. Enter the aperture as an f-number, such as 2.8 or 8.
3. Enter the focus distance to the subject in metres.
4. Choose your sensor, then read the near and far limits of sharp focus.

Depth of field is the range of distances in a photo that appears acceptably sharp. Everything nearer or further than this zone falls progressively out of focus. It is one of the most creative controls in photography, from a portrait with a soft background to a landscape sharp front to back.

Three things set it: the aperture, the focal length and how far away you focus. The sensor size matters too, through the circle of confusion, the size a point can blur to before it looks unsharp. Getting depth of field right is often the difference between a snapshot and a deliberate image.

1. Work out the hyperfocal distance H from focal length, aperture and circle of confusion.
2. Find the near limit from H and the focus distance s.
3. Find the far limit the same way with a minus sign.
4. The depth of field is the far limit minus the near limit.

When you focus at or beyond the hyperfocal distance, the far limit becomes infinity, so everything from the near limit to the horizon is sharp.

A 50 mm lens at f/8 on a full-frame camera, focused 5 metres away, has a hyperfocal distance of about 10.8 metres. The near limit works out to roughly 3.4 metres and the far limit to about 9.2 metres, so the depth of field is about 5.8 metres. Open up to f/2 for a portrait and that zone shrinks dramatically, throwing the background out of focus.

Aperture

A smaller aperture, meaning a bigger f-number, deepens the field; a wide aperture makes it shallow.

Focal Length

Longer lenses give a shallower depth of field at the same aperture and framing.

Focus Distance

The closer you focus, the shallower the depth of field, which is why macro work is so thin.

Sensor Size

Larger sensors give a shallower depth of field for the same field of view, through the circle of confusion.

Depth of field for a 50 mm lens on full frame, focused at 5 metres.

Each stop down roughly doubles the depth of field, until at small apertures the far limit reaches infinity.

Landscapes

Choose an aperture and focus point that keeps foreground and horizon sharp.

Portraits

Pick a wide aperture that softens the background while keeping the eyes sharp.

Product and Macro

Plan the thin depth of field of close-up work and where to focus.

1. Ignoring Focus Distance

Depth of field changes hugely with how close you focus, not just the aperture.

2. Forgetting Sensor Size

The same settings give different depth on a crop sensor than on full frame.

3. Stopping Down Too Far

Very small apertures deepen the field but soften the whole image through diffraction.

4. Trusting the Viewfinder

The viewfinder shows the widest aperture; use the preview or a calculator to judge the real depth.

The formulas are the standard thin-lens model with a typical circle of confusion per sensor. Real sharpness also depends on the lens and your viewing size.

Depth of field is the range of distances in a photo that looks acceptably sharp, set by aperture, focal length, focus distance and sensor size.

Find the hyperfocal distance, then the near and far limits from the focus distance. A 50 mm lens at f/8 focused at 5 m on full frame is sharp from about 3.4 to 9.2 m.

Yes. A smaller aperture, a higher f-number, deepens the field; a wide aperture makes it shallow. Each stop down roughly doubles the depth.

Yes. Longer lenses give a shallower depth of field at the same aperture and framing, which is why telephotos blur backgrounds strongly.

The largest a point of light can blur to while still looking sharp. It is smaller on smaller sensors, which affects depth of field.

Yes. A larger sensor gives a shallower depth of field for the same field of view, all else equal.

The focus distance that gives the deepest depth of field, sharp from half that distance to infinity. Our hyperfocal calculator focuses on it.

Very small apertures deepen depth of field but introduce diffraction, which softens the whole image. Many lenses are sharpest around f/8.

No. The calculator runs entirely in your browser and nothing you enter is stored or sent anywhere.

• Depth of field (Wikipedia).
• Circle of confusion (Wikipedia).
• Hyperfocal distance (Wikipedia).