120 depth-of-field cells — 50mm at f/8 is sharp from 5.2 m to infinity
Every pairing of 12 focal lengths and 10 apertures, worked out as a hyperfocal distance and a near-to-far range. Only one plane is truly in focus; what looks sharp in front of it and behind it is blur that has not yet grown past a point.
What the hyperfocal distance means
Focus there and everything from half that distance out to infinity reads as sharp. It is the setting landscapes lean on, and it buys far more foreground than focusing at infinity does. The halving is not a rule of thumb — it falls straight out of the equation.
Depth of field rests on an agreement
A lens truly focuses on one plane only. What reads as sharp in front of it and behind it is blur that has not yet spread past the size the eye still accepts as a point — the circle of confusion. This table uses 0.03 mm, the common figure for the 35 mm format. Printing large or inspecting at 100 % on screen makes the standard stricter, and the depth shrinks accordingly.
The two axes do not pull equally
Closing the aperture one stop deepens the field by about √2, but doubling the focal length shallows it by a factor of four. Two stops cannot undo one doubling — which is why a longer lens, not a wider aperture, is the surest way to melt a portrait background.
Smaller formats look deeper
With the same focal length and aperture, a smaller format has a smaller circle of confusion, which pushes the hyperfocal distance further away. In practice, though, you reach for a shorter lens to keep the same angle of view, and that effect is far stronger, so the picture ends up deeper.
At a glance
Hyperfocal distance
14 mmf/8 · 0.83 m
20 mmf/8 · 1.69 m
24 mmf/8 · 2.42 m
28 mmf/8 · 3.29 m
35 mmf/8 · 5.14 m
50 mmf/8 · 10.47 m
85 mmf/8 · 30.19 m
100 mmf/8 · 41.77 m
135 mmf/8 · 76.07 m
200 mmf/8 · 166.87 m
300 mmf/8 · 375.3 m
400 mmf/8 · 667.07 m
Worth knowing
- Focus at the hyperfocal distance and everything from half of it to infinity looks sharp.
- One stop moves depth by √2; focal length moves it by the square — the lens wins by far.
- These figures assume the 35 mm format with a 0.03 mm circle of confusion.
- Print large or inspect at 100 % and the usable depth comes out shallower than this.
Common questions
Q. What should I change to blur the background most?
Reach for a longer lens. An aperture stop moves depth by about √2, while focal length works as a square — 100 mm at f/2.8 is shallower than 50 mm at f/1.8.
Q. Where do I focus for a landscape?
At the hyperfocal distance. Everything from half of it to infinity then reads as sharp, which buys nearly twice the foreground that focusing at infinity gives you.
Q. Do smaller sensors really give more depth?
At the same focal length and aperture they give slightly less. But you pick a shorter lens to keep the same angle of view, and that effect is far stronger, so the picture ends up deeper.
Q. Can I trust these numbers as they stand?
They rest on a 0.03 mm circle of confusion. Print large or inspect at 100 % and the standard tightens, so the depth you can actually use is shallower.
Q. Is the smallest aperture always the sharpest?
Depth keeps growing, but past f/16 diffraction pulls overall resolution down. Most lenses look crispest somewhere between f/8 and f/11.