Hyperfocal distance calculator

Name your lens, your aperture and your sensor, and it returns the one distance to focus at for the deepest sharp zone that lens can give — plus the near and far limits, drawn on a scale, and the aperture past which diffraction starts taking sharpness back. Free, no account, nothing stored.

What it does, and why it is here

Focus at infinity and the foreground is soft; focus on the foreground and the horizon goes. Between the two lies the distance where the far limit just reaches infinity while the near limit is as close as it can be — the hyperfocal distance. Focus there and everything from half that distance to infinity is sharp: at 24 mm and f/8 on full frame, focus at 2.4 m and the picture is sharp from 1.2 m to the horizon. That is most landscape photography solved with one number.

The number itself is not hard, but it is not memorable either, because it moves with three things at once: H = f² ÷ (N × c) + f. The focal length is squared and the aperture is not, so doubling the focal length quadruples the answer while closing two stops only halves it. There is no rule of thumb that survives changing lenses.

And the third term, c, the circle of confusion, is not a fact at all — it is a convention about how large the picture will be and how close you will stand to it. That is why two depth-of-field calculators disagree while both being right. This one says which value it used, and lets you change it.

What you fill in

• Focal length in mm, aperture as an f-number, and sensor format — the three that give the hyperfocal distance on their own.
• Focus distance in metres, optional — leave it empty for the hyperfocal distance alone; fill it in to be told exactly what is sharp when you focus somewhere else, which is the more common real question.
• Viewing condition — the convention made adjustable, because it is the one input that is a judgement. The format’s standard, an A4 print at reading distance (×1), a screen (×1.5, which forgives more), or an A2 print (×0.5, which forgives half as much). If you print big, this is the field that stops the calculator lying to you.
• Resolution in megapixels, optional — fill it in and the answer names the aperture beyond which diffraction begins softening this sensor.
• Focus stack, from and to in metres, optional — give both ends of a range and the tool lists the distances to focus at to cover it.

What you get back

• Focus here — the hyperfocal distance, the single number to set on the lens.
• Nearest and furthest sharp point, and the depth of field between them. The far limit reads infinity when you are focused at or past the hyperfocal distance, rather than a large meaningless number.
• A scale from 30 cm to infinity with the sharp band drawn on it: H marks the hyperfocal distance, a dot marks where you focused. It answers “have I gone too far?” faster than three figures do.
• The circle of confusion actually used, stated. A calculator assuming a different one gives a different answer, and you should be able to see which you are getting.
• The diffraction limit — the f-number beyond which the Airy disc spans more than two pixels at your pixel pitch, with a verdict on whether your aperture is inside it or past it. This is the counterweight the rest of the answer needs: closing down buys depth of field and then starts costing sharpness everywhere.
• A focus stacking plan, when you gave a range — how many shots, and the distance for each, arranged so every shot’s near limit lands exactly where the previous one stopped being sharp, with the last one at the hyperfocal distance reaching infinity. If the range cannot be covered in a hundred shots at that aperture, it says so instead of listing them.
• Two tables — the same lens at every aperture, and the same aperture at every focal length, yours in bold. The one to look at when the answer is not what you hoped and you are deciding what to change.

What it does not do

It computes geometry, not the sharpness of your particular lens. A lens that is soft wide open, or soft at the edges, will be soft inside the band the tool draws — depth of field says where the focus is acceptable, not where the optics are good.

Focal lengths are nominal: real lenses breathe, and a “24 mm” focused close may be 22. And it takes the standard thin-lens model, which is accurate at ordinary distances and drifts in true macro work, where magnification rather than distance governs the answer.

Hyperfocal distance chart, full frame

The shape of the trade-off, at the standard circle of confusion.

Two stops of aperture move the answer less than one step of focal length: 24 mm from f/8 to f/11 goes 2.4 m to 1.8 m, while 24 mm to 35 mm at the same f/8 goes 2.4 m to 5.1 m. And the same 24 mm f/8 asks for 2.4 m on full frame but 3.6 m on APS-C, because the smaller sensor is enlarged more and takes a smaller circle of confusion.

Questions

Is this calculator free?

Yes. No account, no e-mail, nothing stored.

Why does the far limit say “infinity” instead of a number?

Because you are focused at or past the hyperfocal distance, and that is what the far limit becomes. There is nothing beyond infinity to report.

Do I have to fill in the focus distance?

No. Leave it empty and you get the hyperfocal distance on its own. Fill it in when the real question is “I focused there — what did I get?”

Another calculator gives me a different answer. Which is right?

Probably both. They are using different circles of confusion. Set the viewing condition here to match how you will actually look at the picture, and the answer becomes the one that matters to you.

Is the hyperfocal distance the sharpest place to focus?

No — it is the deepest. The plane of focus is always the sharpest, and at the hyperfocal distance both the foreground and the horizon sit at the edge of acceptable. If the horizon is the subject, focus on the horizon.

Should I just stop down to f/16 and stop thinking about it?

That is what the diffraction line is there to answer. Past the limit for your sensor, closing down keeps extending the band while softening everything inside it, and on a dense sensor that point arrives sooner than photographers expect. Focus stacking is the way past it.

Does a crop sensor really give more depth of field?

At the same focal length and aperture, yes on the sensor — but you stand further back or use a shorter lens to frame the same scene, and that is where most of the difference actually comes from.

Does it change with a teleconverter or extension tube?

Yes. A teleconverter multiplies the focal length and the f-number, so enter the effective values. An extension tube changes the focusing geometry and puts you outside the thin-lens model.

Sources and further reading

• Hyperfocal distance — the definition and the two formulations.
• Circle of confusion — why the third term is a convention.
• Diffraction limit — the Airy disc, and why stopping down eventually costs.