Hyperfocal Distance

The hyperfocal distance is the closest focus distance at which a lens, set to a specific aperture and focal length, keeps everything from half that distance to infinity within the depth of field. When you focus at the hyperfocal distance, you achieve the maximum depth of field available for that aperture and focal length combination. Focusing beyond the hyperfocal distance towards infinity retains sharpness at distance but sacrifices near sharpness needlessly; focusing at the hyperfocal distance extends sharp focus further into the foreground.

The hyperfocal distance varies with aperture and focal length. Shorter focal lengths and smaller apertures (higher f-numbers) produce shorter hyperfocal distances, meaning the camera can be focused closer while maintaining sharpness to infinity. On M43, where wide-angle lenses have shorter native focal lengths due to the crop factor, hyperfocal distances are generally shorter than on full-frame cameras at equivalent fields of view. This makes maximising depth of field more practical on M43 for landscape work at a given aperture.

Focusing beyond the hyperfocal distance wastes available depth of field. If the hyperfocal distance is 3 metres and you focus at infinity, everything from 3 metres to infinity is sharp, but so is everything from 1.5 metres to 3 metres, which is already within the depth of field. By focusing at the hyperfocal distance rather than infinity, the near sharp distance moves from 3 metres to 1.5 metres, adding sharpness in the foreground without losing sharpness at distance.

Calculating the hyperfocal distance requires the focal length, aperture, and circle of confusion value for the sensor. For M43, a commonly used circle of confusion is 0.011mm, smaller than the full-frame equivalent of 0.029mm because the M43 sensor is more frequently enlarged more for a given print or display size. The m43lab Depth of Field Calculator computes the hyperfocal distance, near limit, and far limit for any focal length and aperture combination on M43.