Hyperfocal Distance by Aperture

Hyperfocal distance and aperture

Set your focus to the hyperfocal distance and that's the nearest point you can pick while still holding infinity at acceptable sharpness. You find it with H = f² / (N·c) + f. Here f is the focal length in mm, N is the aperture f-number, and c is the circle of confusion (roughly 0.03 mm on full-frame, 0.02 mm on APS-C). Take a 24 mm lens at f/8 on full-frame with c = 0.03, and you get H ≈ 2.4 m. Focus there and the sharp zone runs from H/2 ≈ 1.2 m all the way to infinity.

Applications

Think landscape work where you want everything sharp in a single frame, or street photography shot with zone focus (you prefocus at H and fire without waiting on autofocus). Architecture and real estate lean on it too, along with any scene where both the foreground and the far background have to hold up at once.

FAQ

Why does stopping down further not always help? Once you get past roughly f/11–f/16, diffraction starts softening the whole frame, and that eats into the extra depth of field you were after.

Does the circle of confusion change with sensor size? It does. A smaller sensor calls for a smaller c, since you're enlarging the image more to reach the same print size, and that ends up pushing H farther out.

Is hyperfocal a hard cutoff? Not really. It rests on a perceptual idea of what counts as sharp, so if you pixel-peep at 100 % you'll usually catch infinity looking a touch softer than the actual point of focus.