How this calculator works
When you focus at the hyperfocal distance, the far limit of acceptable sharpness reaches infinity. Everything from half the hyperfocal distance to the horizon is then sharp enough for the chosen circle of confusion, so a landscape photographer can set focus once and keep the foreground and horizon together. The distance grows with the square of the focal length, which is why wide lenses have short hyperfocal distances and long lenses have very long ones. It falls as the aperture closes, so stopping down from f/8 to f/16 halves the hyperfocal distance. The circle of confusion is taken as the sensor diagonal divided by 1500, the conventional value for a print viewed at a normal distance.
Formula
circle of confusion c = sensor diagonal / 1500. hyperfocal distance H = f^2 / (N x c) + f, where f is the focal length, N the f-number and c and f are in the same units. The nearest sharp point when focused at H is H / 2.
Worked example
A 50 mm lens at f/8 on a full-frame sensor has a circle of confusion of 43.267 / 1500 = 0.02884 mm. In metres, H = 0.05 squared / (8 x 0.00002884) + 0.05 = 10.884 metres, so the near limit is 5.442 metres. The same lens at 24 mm and f/8 gives H = 0.024 squared / (8 x 0.00002884) + 0.024 = 2.520 metres, with a near limit of 1.260 metres, which is why wide lenses are used for interiors and landscapes.
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Frequently asked questions
Should I always focus at the hyperfocal distance?
Only when you need everything from a near foreground to infinity sharp. If the important subject is closer than half the hyperfocal distance, focusing there would leave it soft, so focus on the subject and accept a softer background.
Does the hyperfocal distance depend on print size?
Yes, through the circle of confusion. A large print viewed closely needs a smaller circle, which pushes the hyperfocal distance further away. The 1/1500 convention assumes a modest print seen from roughly a print diagonal away.
Why is my hyperfocal distance different from another calculator?
The usual cause is a different circle of confusion, often 0.03 mm for full frame instead of 0.0288 mm, or the small approximation of dropping the final plus f term. The difference is a few percent and disappears in practice.
Do hyperfocal focus scales on old lenses match?
They use the manufacturer's chosen circle of confusion, which often differs from the modern convention. Treat the engraved scale as a guide and check the result on a test shot.