Depth of field calculator

A depth of field calculator turns four photographic inputs into the near limit, far limit, and total zone of acceptable sharpness around your focus plane. Enter focal length in millimetres, aperture as an f-number, focus distance in metres, and the circle of confusion in millimetres for your sensor format; the tool returns hyperfocal distance plus near, far, and total depth of field in metres, with step-by-step substitution you can check by hand. Portrait, landscape, product, and macro shooters all need the same near-and-far numbers when choosing aperture and subject distance without opening a spreadsheet.

What depth of field means and how the formulas work

Depth of field is the distance range in front of and behind the focus plane where blur remains below a chosen circle of confusion. In the standard photographic model you need four positive numbers: focal length f in millimetres, aperture N as the dimensionless f-number, subject focus distance s in metres, and circle of confusion diameter c in millimetres.

The hyperfocal distance H equals f squared over N times c, plus f; when you focus at H, everything from roughly H over two to infinity is acceptably sharp for that c. For a general subject distance the near limit is s times (H minus f) divided by (H plus s minus two f), and the far limit is s times (H minus f) divided by (H minus s) whenever s is less than H.

When focus is at or beyond the hyperfocal distance the far limit becomes infinite and total depth of field is reported as infinite rather than a finite span. Smaller apertures (larger N), shorter focal lengths, and larger CoC values all widen the zone; longer glass, wider apertures, and tighter CoC values shrink it.

Teachers and camera clubs care about the non-positive distance rejection as much as the happy path: a zero-metre subject distance is not a valid photographic setup, and a silent clamp to a tiny epsilon would hide bad input. The check path recomputes hyperfocal, near, and far with the same fixed rounding used for published fields, so a successful response always ships with steps you can assert in tests or field notes.

Practical tips, sensor CoC choices, and related searches

Pick a circle of confusion that matches how you will view the image: about zero point zero three millimetres is a common full-frame print-oriented default; APS-C bodies often use roughly zero point zero one nine millimetres, and Micro Four Thirds smaller still. Keep focus distance in metres and focal length in millimetres so you do not mix units; the solver converts subject distance to millimetres internally before applying the hyperfocal formulas and converts results back to metres.

Prefer sending numbers rather than pre-formatted strings when you control the client; string numbers are accepted only when they match a strict finite numeric pattern. When teaching, pair examples: fifty millimetres at f slash two point eight focused at five metres with CoC zero point zero three yields a modest total DOF around the subject; eighty-five millimetres at f slash one point eight focused at two metres produces a thin portrait plane; and the same fifty millimetre lens focused far beyond hyperfocal demonstrates infinite far and null total.

This landing targets people searching for a depth of field calculator, DOF near far, hyperfocal distance, or aperture and focal length DOF online; it is not a diffraction blur estimator, not a bokeh simulator, and not a lens rental catalog. Prefer this capability when you already know f, N, s, and c and only need the near far total triple; if your source is a crop factor discussion, choose CoC for the sensor first.