# Hyperfocal Distance and Depth of Field, Worked Out

What hyperfocal distance actually is, why depth of field tables disagree with each other, and what stopping down for sharpness really costs you in shutter speed.

---

- **Canonical URL:** https://dothecalculation.com/blog/hobby/depth-of-field-and-exposure-guide
- **Category:** Hobbies & Leisure Utilities
- **Author:** Do The Calculation Team
- **Published:** 2026-09-20
- **Reading time:** 17 min read
- **Publisher:** Do The Calculation (https://dothecalculation.com)
- **Methodology:** https://dothecalculation.com/methodology

---

Two numbers decide whether a landscape photograph is sharp front to back: where you focus, and what aperture you use. Both are computable, and the arithmetic is worth understanding rather than trusting to an app, because every depth of field figure you have ever read rests on one assumption that nobody agrees on.

> **The assumption underneath everything** — Depth of field is not a physical boundary. Only one plane is ever in true focus; everything else is a blur circle that grows with distance from that plane. "Sharp" means the blur circle is small enough that a viewer cannot see it — which depends on how big the print is, how close they stand, and how good their eyes are. That threshold is the circle of confusion, and it is a convention, not a constant.

## The circle of confusion, and why tables disagree

Pick a different circle of confusion and every depth of field number changes. Published values for a full-frame 35 mm sensor commonly sit between about 0.025 mm and 0.033 mm, which is a spread of roughly 30%, and it propagates straight into the answers. Our calculator uses 0.03 mm for full frame and scales it by the crop factor.

**Circle of confusion by format, on the 0.03 mm full-frame convention**
| Format | Crop factor | Circle of confusion |
| --- | --- | --- |
| Full frame (35 mm) | 1.0 | 0.0300 mm |
| APS-C (Nikon, Sony, Fuji) | 1.5 | 0.0200 mm |
| APS-C (Canon) | 1.6 | 0.0187 mm |
| Micro Four Thirds | 2.0 | 0.0150 mm |

The reason it scales with crop factor is enlargement. A smaller sensor has to be blown up more to reach the same print size, so the same physical blur circle on the sensor becomes a larger blur on the wall. Tightening the threshold in proportion keeps the standard consistent.

> **So treat the output as a good estimate** — If a calculator tells you the near limit is 2.34 m, do not plan a shot that depends on 2.34 m being exactly right. Every such figure carries the circle-of-confusion choice inside it. This is also why two apps can give you different numbers and both be correct.

## Hyperfocal distance

The hyperfocal distance is the focus distance at which the far limit of depth of field reaches infinity. Focus there and everything from half that distance out to infinity falls within your sharpness threshold. It is the single most useful number in landscape photography, and it is why focusing on the horizon is usually a mistake — you throw away everything from half the hyperfocal distance to the horizon for no gain.

**Hyperfocal distance and the depth of field limits**

```
H = f² ÷ (N × c) + f
Near limit = s (H − f) ÷ (H + s − 2f)
Far limit  = s (H − f) ÷ (H − s)
```
- f is focal length in mm, N is the f-number, c is the circle of confusion in mm, s is the focus distance in mm.
- When s reaches H − f the far limit denominator collapses and the far limit is infinity. That is the definition of the hyperfocal distance restated.
- These are the standard thin-lens depth of field relations. They are exact given a circle of confusion; the uncertainty is entirely in c.

**A 24 mm lens on full frame: where to focus**
| Aperture | Hyperfocal distance | Focus there and you get |
| --- | --- | --- |
| f/8 | 2.42 m | 1.21 m to infinity |
| f/11 | 1.77 m | 0.88 m to infinity |

At f/11 on a 24 mm lens, focusing at 1.77 m gives you sharpness from under a metre all the way out. Focus on the mountain instead and the foreground rocks two metres away go soft, which is the commonest landscape mistake there is.

Tool: [Work out your own hyperfocal distance](https://dothecalculation.com/calculators/photography-dof-hyperfocal-calculator) — Near limit, far limit and hyperfocal distance for your sensor format, focal length, aperture and focus distance.

## What actually moves depth of field

Three things, and they do not contribute equally. Here is the same subject at 3 m, shot four ways, on full frame.

**Subject at 3 m — what each variable does**
| Setup | Near | Far | Total depth of field |
| --- | --- | --- | --- |
| 50 mm at f/2.8 | 2.73 m | 3.33 m | 0.60 m |
| 50 mm at f/8 | 2.34 m | 4.19 m | 1.85 m |
| 50 mm at f/16 | 1.92 m | 6.92 m | 5.00 m |
| 85 mm at f/8 | 2.74 m | 3.32 m | 0.59 m |
| 24 mm at f/8 | 1.34 m | infinity | infinity |

Two things stand out. Focal length dominates: going from 24 mm to 85 mm at the same aperture and distance takes you from infinite depth of field to 59 centimetres. And depth of field is not symmetrical — at 50 mm f/8 there is 0.66 m in front of the subject and 1.19 m behind it. The old rule that it extends one third in front and two thirds behind is roughly right at moderate distances, and breaks down badly close up and far away.

Sensor size matters too, but indirectly. The same 50 mm lens at f/8 focused at 3 m gives 1.85 m of depth on full frame and 1.17 m on APS-C — but it is also a much tighter framing on APS-C. Compare like for like, at the same field of view, and the smaller sensor gives you more depth of field, which is why phone cameras have to fake background blur in software.

## What stopping down costs you

Depth of field is never free. Every stop you close down halves the light reaching the sensor, and you pay for it in shutter speed or in ISO. Exposure value is the clean way to see the trade, because it collapses aperture and shutter speed into one number.

**Exposure value**

```
EV = log₂(N² ÷ t)
EV100 = EV − log₂(ISO ÷ 100)
Illuminance in lux = 2.5 × 2^EV100
```
- N is the f-number and t the shutter speed in seconds. Every whole EV step is one stop: half the light.
- The lux relation comes from E = 2^EV × C ÷ ISO with C the incident meter calibration constant, which ISO 2720:1974 permits in the range 240 to 400. Taking the conventional C = 250 at ISO 100 gives the 2.5 × 2^EV100 form quoted above.

**Common settings as exposure values**
| Settings at ISO 100 | EV100 | Roughly |
| --- | --- | --- |
| f/16, 1/100 s | 14.64 | 64,000 lux — bright sun |
| f/8, 1/250 s | 13.97 | 40,000 lux — hazy sun |
| f/2.8, 1/60 s | 8.88 | 1,176 lux — bright indoors |
| f/1.4, 1/30 s | 5.88 | 147 lux — dim indoors |

> **Sunny 16 does not land on a round number** — The Sunny 16 rule says that in bright sunlight you can shoot at f/16 with a shutter speed of one over the ISO. At ISO 100 that is f/16 at 1/100 s, and it computes to EV100 14.64, not a tidy 15. Any chart that puts full sun at exactly EV 15 has rounded, and a tool that starts its bright-sun band at 15 will label the canonical Sunny 16 setting as overcast.

Now the trade is easy to read. Going from f/2.8 to f/16 on that 50 mm lens takes depth of field from 0.60 m to 5.00 m, and the aperture change alone is 2 x log₂(16 / 2.8) = 5.03 stops. Exposure value is what stays fixed: if you were correctly exposed at f/2.8 and 1/60 s, you are at EV100 8.88, and holding that same EV at f/16 means a shutter speed of 0.54 s, or about 1/1.8. That is a tripod, or a large ISO increase, and it is the real reason landscape photographers carry tripods.

Tool: [Convert settings to EV and lux](https://dothecalculation.com/calculators/photography-exposure-value-calculator) — Exposure value from aperture, shutter speed and ISO, with the illuminance in lux and foot-candles and the equivalent settings that give the same exposure.

## And why f/22 is not the answer

If stopping down adds depth of field, it is tempting to go as far as the lens allows. It does not work, because a second effect runs the other way. As the aperture narrows, diffraction spreads each point of light into a larger disc, and past a certain f-number that spreading costs you more detail across the whole frame than the extra depth of field gains you at the edges.

The point where the two cross depends on the sensor and on how large you print, so treat published "optimal aperture" figures as starting points rather than as facts about your lens. The practical version most photographers settle on is simple: use the widest aperture that gets the depth of field you actually need, rather than the narrowest the lens offers.

## A hyperfocal chart for common wide and standard lenses

Hyperfocal distance is most useful as a number you already know when you arrive at a location. Here it is for the focal lengths landscape photographers use most, on a full-frame sensor with the 0.03 mm circle of confusion this guide uses throughout. The figure in brackets is the near limit when you focus exactly at the hyperfocal distance, which is always half of it.

**Hyperfocal distance on full frame, with the near limit when focused there (metres)**
| Focal length | f/8 | f/11 | f/16 |
| --- | --- | --- | --- |
| 14 mm | 0.83 (0.42) | 0.61 (0.30) | 0.42 (0.21) |
| 16 mm | 1.08 (0.54) | 0.79 (0.40) | 0.55 (0.27) |
| 20 mm | 1.69 (0.84) | 1.23 (0.62) | 0.85 (0.43) |
| 24 mm | 2.42 (1.21) | 1.77 (0.88) | 1.22 (0.61) |
| 28 mm | 3.29 (1.65) | 2.40 (1.20) | 1.66 (0.83) |
| 35 mm | 5.14 (2.57) | 3.75 (1.87) | 2.59 (1.29) |
| 50 mm | 10.47 (5.23) | 7.63 (3.81) | 5.26 (2.63) |

Two patterns are worth memorising. Wide lenses have astonishingly short hyperfocal distances: at 14 mm and f/8, focusing at 83 centimetres gives sharpness from 42 centimetres to infinity, which is why ultra-wide lenses are so forgiving. And the hyperfocal distance grows with the square of focal length, so a 50 mm lens at f/8 needs you to focus more than ten metres away. At longer focal lengths, putting everything from foreground to horizon in focus in a single frame stops being practical.

> **Focus a little beyond the hyperfocal distance, not before it** — If you misjudge and focus slightly short of the hyperfocal distance, infinity drops out of the sharp zone and the horizon goes soft. If you focus slightly beyond it, you lose a little at the near end but keep infinity. Because distance scales on lenses are approximate and your estimate of distance is too, erring long is the safer mistake.

## The other extreme: thin depth of field for portraits

Landscape photographers fight for depth of field. Portrait photographers spend money to get rid of it. The same formulas describe both, and the numbers at wide apertures are startlingly small.

**Depth of field for head-and-shoulders portraits, full frame**
| Lens and aperture | Subject distance | Near limit | Far limit | Total depth of field |
| --- | --- | --- | --- | --- |
| 85 mm at f/1.8 | 2 m | 1.972 m | 2.029 m | 5.7 cm |
| 85 mm at f/2.8 | 2 m | 1.956 m | 2.046 m | 8.9 cm |
| 85 mm at f/1.8 | 3 m | 2.936 m | 3.067 m | 13.1 cm |
| 50 mm at f/1.8 | 2 m | 1.919 m | 2.088 m | 16.9 cm |
| 135 mm at f/2 | 3 m | 2.972 m | 3.029 m | 5.7 cm |

At 85 mm and f/1.8, two metres from the subject, the sharp zone is under six centimetres deep. That is less than the distance from the tip of a nose to the eyes, which is why portrait photographers focus on the nearer eye and accept that the ear will be soft. Stopping down one and a third stops to f/2.8 buys only about three more centimetres, while stepping back to three metres more than doubles the depth at the same aperture — but also changes the framing.

> **Thin depth of field punishes small movements** — With a 5.7 cm sharp zone, the subject leaning forward a few centimetres after you focus is enough to move the eyes out of focus. At very wide apertures, refocus often, use continuous autofocus with eye detection if your camera has it, and take several frames. A technically sharp portrait at f/1.8 is a timing problem as much as a focusing one.

## Close up, depth of field almost disappears

Depth of field shrinks rapidly as you get closer to the subject, which is the single biggest challenge in close-up and macro photography.

**Half a metre from the subject, full frame**
| Lens and aperture | Near limit | Far limit | Total depth of field |
| --- | --- | --- | --- |
| 50 mm at f/8 | 0.479 m | 0.523 m | 4.3 cm |
| 100 mm at f/8 | 0.495 m | 0.505 m | 1.0 cm |
| 100 mm at f/16 | 0.491 m | 0.510 m | 1.9 cm |

At half a metre with a 100 mm lens, even f/16 gives under two centimetres of sharpness. This is why close-up photographers photograph flowers edge-on rather than face-on when they want the whole bloom sharp, and why many use focus stacking: taking several frames focused at slightly different distances and combining the sharp parts in software. Treat these figures as approximate: the standard formulas start to lose accuracy as you approach true macro magnifications, where a different form of the calculation applies.

## Sensor size, done properly: equivalent aperture

The body of this guide noted that a smaller sensor gives more depth of field at the same framing. It is worth seeing the size of the effect, because it explains why lenses for smaller sensors are described with an equivalent aperture.

**The same framing of a subject 3 m away, on three formats**
| Format and lens | Aperture | Total depth of field |
| --- | --- | --- |
| Full frame, 50 mm | f/4 | 86.7 cm |
| APS-C (1.5×), 33 mm | f/4 | 137.3 cm |
| APS-C (1.5×), 33 mm | f/2.7 | 89.1 cm |
| Micro Four Thirds (2×), 25 mm | f/4 | 186.6 cm |
| Micro Four Thirds (2×), 25 mm | f/2 | 87.5 cm |

**Equivalent aperture for depth of field**

```
Full-frame equivalent f-number = actual f-number × crop factor
```
- A 25 mm f/2 on Micro Four Thirds gives about the same framing and depth of field as a 50 mm f/4 on full frame. The table confirms it: 87.5 cm against 86.7 cm.
- The equivalence is for depth of field and framing only. Exposure is set by the actual f-number: f/2 is f/2 for brightness on any sensor.

This is the honest answer to the recurring argument about whether small-sensor lenses are really as fast as their markings. For exposure they are exactly as fast as marked. For background blur at the same framing, they behave like a lens stopped down by the crop factor.

## Equivalent exposures: the same EV, many settings

Every exposure value corresponds to a whole family of aperture and shutter speed pairs that let in the same total light. Choosing among them is choosing between depth of field and motion.

**Every pair gives EV 12 at ISO 100**
| Aperture | Shutter speed | What changes |
| --- | --- | --- |
| f/2.8 | about 1/500 s | Shallowest depth of field, freezes motion |
| f/4 | 1/250 s |  |
| f/5.6 | about 1/125 s |  |
| f/8 | 1/60 s | The usual landscape starting point |
| f/11 | about 1/30 s | Getting risky hand-held with longer lenses |
| f/16 | 1/15 s | Deepest depth of field, needs support |

The shutter speeds are rounded to the standard marked values, which is how cameras display them; the exact figures differ by a few percent because the f-number sequence is itself rounded. The trade across the table is the one this guide keeps returning to: every stop of depth of field you gain is a stop of shutter speed you give up, unless you raise the ISO instead.

## Neutral density filters: buying slower shutter speeds on purpose

Sometimes the problem runs the other way. You want a long shutter speed to blur water or clouds, or a wide aperture in bright light, and the scene is simply too bright. A neutral density filter cuts the light by a fixed factor without changing its colour.

**Neutral density filter strength**

```
Stops of reduction = log₂(filter factor)
```
- Filters are often labelled by their factor: ND8 lets through one eighth of the light.
- Each stop doubles the shutter speed, so a filter factor multiplies the shutter time directly.

**What common filters do to a 1/125 s exposure**
| Filter | Stops | New shutter speed |
| --- | --- | --- |
| ND2 | 1 | 1/60 s (0.016 s) |
| ND4 | 2 | 1/30 s (0.032 s) |
| ND8 | 3 | 1/15 s (0.064 s) |
| ND64 | 6 | about 1/2 s (0.512 s) |
| ND1000 | about 10 | 8 s |

The ND1000 is the one that changes pictures: it turns a hand-held 1/125 s into an 8-second exposure, long enough to smooth moving water into mist. It is also where the exposure value arithmetic in this guide earns its keep, because the scene is too dark to meter through reliably once the filter is on. Meter without the filter, then apply the factor.

## Common depth of field and exposure mistakes

- **Focusing on the horizon for landscapes.** You throw away everything nearer than half the hyperfocal distance for no gain. Focus at the hyperfocal distance, or just beyond it.
- **Stopping down as far as possible.** Diffraction softens the whole frame past a point. Use the widest aperture that gives the depth you need.
- **Comparing depth of field across formats by f-number alone.** Multiply by the crop factor to compare like with like.
- **Trusting a depth of field figure to the centimetre.** Every figure depends on the circle of confusion chosen. Treat it as a good estimate and leave margin.
- **Metering through a very dark ND filter.** Meter without it, then extend the shutter by the filter factor.
- **Forgetting the shutter speed when you stop down.** Five stops of depth of field is five stops of shutter speed. Check that the new speed is still hand-holdable before you shoot.

## What a stricter sharpness standard does to the numbers

Everything above uses a 0.03 mm circle of confusion. If you print large, view your images at full size on screen, or simply want a stricter standard of sharpness, you use a smaller circle of confusion, and every depth of field figure tightens. Here is the effect on a single setting, a 24 mm lens at f/11 on full frame.

**24 mm at f/11, full frame, under different sharpness standards**
| Circle of confusion | Hyperfocal distance | Near limit when focused there |
| --- | --- | --- |
| 0.033 mm (lenient) | 1.61 m | 0.81 m |
| 0.030 mm (this guide) | 1.77 m | 0.88 m |
| 0.025 mm | 2.12 m | 1.06 m |
| 0.020 mm | 2.64 m | 1.32 m |
| 0.015 mm (strict) | 3.51 m | 1.76 m |

Halving the circle of confusion from 0.030 mm to 0.015 mm doubles the hyperfocal distance, pushing the near limit from under a metre to nearly two. If your foreground rocks are 1.2 metres away, whether they count as sharp depends entirely on which row you believe. A practical approach many landscape photographers use is to work from a stricter figure than the one printed on their lens scale, which builds in margin for large prints.

## Sources

- ISO 2720:1974, Photography — General purpose photographic exposure meters (photoelectric type) — guide to product specification, for the incident meter calibration constant C and its permitted range: https://www.iso.org/standard/7690.html
- The depth of field and hyperfocal relations are the standard thin-lens results and are exact given a circle of confusion; no source can supply the circle of confusion itself, because it is a viewing convention rather than a measurement.

## Where to go next

If you point a lens at the sky, the limits change. [How much magnification can my telescope actually use](/blog/hobby/telescope-magnification-guide) covers the aperture-driven resolution limit, exit pupil and the magnification ceiling, which are the astronomical equivalents of the trade-offs on this page.

## Common questions

**What is hyperfocal distance?**

The focus distance at which the far limit of depth of field reaches infinity. Focus there and everything from roughly half that distance out to infinity is within your sharpness threshold. On full frame at 24 mm and f/11 it is 1.77 m, giving sharpness from 0.88 m to infinity.

**Why do depth of field calculators give different answers?**

Because they assume different circles of confusion. Published values for full frame range from about 0.025 mm to 0.033 mm, and that 30% spread feeds straight into the result. Both calculators can be right; they are answering the question against different sharpness standards.

**Is depth of field really one third in front and two thirds behind?**

Roughly, at moderate distances. At 50 mm, f/8, focused at 3 m on full frame, it is 0.66 m in front and 1.19 m behind — close to the rule. Very close up it approaches half and half, and near the hyperfocal distance the rear extends to infinity, so the ratio breaks down completely.

**Does a smaller sensor give more depth of field?**

At the same field of view and aperture, yes, because it needs a shorter focal length to frame the same scene. With the same lens on both bodies the smaller sensor actually shows less, but it is also a tighter crop, which is not a fair comparison.

**How many stops is f/2.8 to f/16?**

Just over five: 2 x log2(16 / 2.8) = 5.03 stops. If you were correctly exposed hand-holding at f/2.8 and 1/60 s, the same exposure at f/16 needs 0.54 s, about 1/1.8 of a second. Both settings sit at the same exposure value, EV100 8.88, which is the point of the EV scale.

**Should I always use the smallest aperture for landscapes?**

No. Diffraction spreads each point of light into a larger disc as the aperture narrows, and past a point it costs more sharpness across the frame than the extra depth of field gains at the edges. Use the widest aperture that gives you the depth of field you actually need.

**What is the hyperfocal distance for a 24 mm lens?**

On full frame with a 0.03 mm circle of confusion, it is 2.42 m at f/8, 1.77 m at f/11 and 1.22 m at f/16. Focus there and everything from half that distance to infinity is acceptably sharp.

**How much depth of field does an 85 mm f/1.8 give?**

About 5.7 cm at two metres on full frame, and about 13.1 cm at three metres. That is less than the depth of a face, which is why portrait photographers focus on the nearer eye.

**What is equivalent aperture?**

The f-number multiplied by the crop factor, giving the full-frame aperture that produces the same depth of field at the same framing. A 25 mm f/2 on Micro Four Thirds gives about the same depth of field as a 50 mm f/4 on full frame. It does not change exposure; f/2 is f/2 for brightness.

**How many stops is an ND1000 filter?**

About 10 stops, since log₂(1000) is 9.97. It multiplies the shutter time by 1000, turning 1/125 s into 8 seconds.

**Why is depth of field so thin in close-up photography?**

Depth of field shrinks rapidly as the subject gets closer. A 100 mm lens at f/16 half a metre away gives under 2 cm of sharpness. Close-up photographers compensate with careful subject alignment or by focus stacking several frames.

---

_Source: [Do The Calculation](https://dothecalculation.com/blog/hobby/depth-of-field-and-exposure-guide). Quote freely with attribution and a link to this page._