Depth of Field Calculator

Depth of field is the range of distances that appears acceptably sharp around the exact plane of focus. It is not a hard wall where sharpness suddenly ends. Detail gradually becomes less distinct in front of and behind the subject, and the near and far limits represent the points where blur reaches the selected circle of confusion. Photographers use these limits to balance subject separation, environmental detail, and focusing tolerance before taking a picture. This calculator uses focal length, f-number, subject distance, and circle of confusion. It first finds hyperfocal distance by dividing focal length squared by aperture times circle of confusion, then adding one focal length. The near focus limit is derived from the hyperfocal and subject distances. The far limit uses the corresponding denominator in the opposite direction; when the subject is at or beyond the hyperfocal distance, that far limit extends to infinity. All optical calculations are performed in millimeters and displayed in meters. A wider aperture such as f/2 produces a shallower sharp zone than f/8 when the other settings stay fixed. A longer focal length also tends to reduce depth of field for the same framing distance, while focusing farther away expands it. Sensor format enters indirectly through the circle of confusion. A commonly used value is 0.03 mm for full-frame cameras, about 0.02 mm for APS-C, and roughly 0.015 mm for Micro Four Thirds, although standards vary. Hyperfocal focusing is especially useful for landscapes and street photography. When a lens is focused at the hyperfocal distance, the calculated sharp range extends from approximately half that distance to infinity. This can preserve foreground detail without wasting as much focus range behind infinity. For portraits, the near and far limits help determine whether both eyes or several people will remain acceptably sharp. Results are planning estimates rather than guarantees of perceived sharpness. Final appearance also depends on viewing size, viewing distance, sensor resolution, lens performance, diffraction, motion, and the viewer's eyesight. Macro photography can require formulas that account for magnification and effective aperture, so ordinary subject-distance equations become less accurate at very close range. Use the calculated limits as a practical starting point, then inspect critical images at the intended output size.