Come funziona il calcolo
Hyperfocal distance is computed as H = f squared / (N x c) + f, where f is focal length, N the f-number and c the circle of confusion for your sensor. Near and far limits come from the standard depth-of-field pair: near = (H x s) / (H + (s - f)) and far = (H x s) / (H - (s - f)), with s your focus distance. When that far denominator falls to zero or below, the tool prints infinity.
The Sensor (CoC) dropdown is the setting most people overlook, and it feeds c directly: 0.030 mm for full frame, 0.020 mm for APS-C Nikon / Sony, 0.019 mm for APS-C Canon, 0.015 mm for Micro Four Thirds, 0.011 mm for 1-inch, plus 0.038 and 0.044 mm for medium format. Focal length, aperture and focus distance default to 24 mm, f/8 and 3 m, switchable to feet.
Circle of confusion is a convention rather than a measurement. These values work out to roughly the sensor diagonal divided by 1,440, which assumes a modest enlargement viewed at a normal distance. Pixel-peep at 100% and your usable depth of field will be noticeably shallower than the table suggests. The comparison rows also run f/2.8 through f/22 whether or not your lens offers them, and diffraction is not modelled, so the gain at f/22 is overstated.
Domande frequenti
Where should I focus for a sharp landscape? +
Focus at the hyperfocal distance shown and everything from half that distance to infinity falls within the acceptable-sharpness limits. At the default 24 mm, f/8, full frame, that means focusing about 2.42 m away for sharpness from roughly 1.21 m onward.
Why does the far limit show the infinity symbol? +
Once your focus distance reaches or exceeds the hyperfocal distance, the far limit is unbounded. The tool detects that H - (s - f) has dropped to zero or below and prints the infinity symbol rather than an implausibly large number.
What circle of confusion should I use for APS-C? +
The presets are 0.020 mm for Nikon and Sony APS-C and 0.019 mm for Canon APS-C, reflecting their slightly different sensor sizes. Smaller sensors take a smaller circle of confusion because the captured image must be enlarged more to reach the same print size.
Does stopping down to f/22 really give more sharpness? +
The table shows depth of field still growing at f/22, but it does not model diffraction, which softens the entire frame at small apertures. On most modern lenses f/8 to f/11 is the practical limit before diffraction cancels out the extra depth.
Is hyperfocal focusing the same as focusing on infinity? +
No. Focusing at infinity throws away the near half of your available depth of field. Focus at the hyperfocal distance instead and you keep infinity acceptably sharp while gaining everything from half the hyperfocal distance forward, which the tool shows for you.
