Depth of field·100 mm f/2
100 mm f/2
166.77
Hyperfocal distance
83.38 m — Sharp from here to infinity

100 mm f/2 depth of field — hyperfocal 166.77 m

A 100 mm lens at f/2 has a hyperfocal distance of 166.77 m; focus there and everything from 83.38 m to infinity reads as sharp. At a subject 2 m away the sharp band is 0.046 m.

Subject distance

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.

  • 0.5 m0.499 — 0.5 mDepth 0.002 m
  • 1 m0.995 — 1.01 mDepth 0.011 m
  • 2 m1.977 — 2.02 mDepth 0.046 m
  • 3 m2.949 — 3.05 mDepth 0.104 m
  • 5 m4.857 — 5.15 mDepth 0.294 m
  • 10 m9.439 — 10.63 mDepth 1.192 m

Format

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.

  • Full frame166.77 m2 m · 0.046 m
  • APS-C250.1 m2 m · 0.03 m
  • Micro Four Thirds333.43 m2 m · 0.023 m

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.

Nearby cells

100 mm
185.29 m
100 mm
119.15 m
85 mm
120.5 m
135 mm
303.89 m

Same lens, other apertures

f/1.4
238.2 m
f/1.8
185.29 m
f/2
166.77 m
f/2.8
119.15 m
f/4
83.43 m
f/5.6
59.62 m
f/8
41.77 m
f/11
30.4 m
f/16
20.93 m
f/22
15.25 m

Same aperture, other lenses

14 mm
3.28 m
20 mm
6.69 m
24 mm
9.62 m
28 mm
13.09 m
35 mm
20.45 m
50 mm
41.72 m
85 mm
120.5 m
100 mm
166.77 m
135 mm
303.89 m
200 mm
666.87 m
300 mm
1500.3 m
400 mm
2667.07 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 is the hyperfocal distance of 100 mm at f/2?

166.77 m. Focus there and everything from 83.38 m to infinity reads as sharp.

Q. How much stays sharp around a subject 2 m away?

The sharp band is 0.046 m. Focused on the eyes, that is what decides whether the nose and ears fall inside it.

Q. What happens on a smaller format?

The hyperfocal distance becomes 250.1 m on APS-C and 333.43 m on Micro Four Thirds, with the very same lens mounted.

Q. How much does one stop change things?

You land on f/2.8, which pulls the hyperfocal distance closer and deepens the field by about √2.