The Sunny 16 Rule and Exposure Value
Written by Abin Alex and Anu Joseph.
Abstract
The Sunny 16 rule states that on a sunny day with distinct shadows, an aperture of f/16 and a shutter speed of one over the ISO give a well-exposed picture without a meter. Exposure value (EV) turns the rule into a single number: f/16 at 1/125 and ISO 100 is EV 15. This guide shows how weather shifts the rule, how to adapt it to another ISO or shutter speed, how to read an EV chart, and how light value relates to EV. It also gives exercises for practice. It is written for photographers and cinematographers.
Keywords: Sunny 16 rule; exposure value; light value; ISO; exposure estimation
- What is the Sunny 16 rule?
- How does Sunny 16 change with the weather?
- How do I use Sunny 16 with another ISO or shutter speed?
- What is exposure value (EV)?
- How do I read an EV chart?
- What EV numbers match common light?
- How does ISO change EV?
- How is Sunny 16 linked to EV 15?
- What is light value (LV)?
- What is the difference between EV 15 and +1 EV compensation?
- How can I practise Sunny 16 and EV?
- How do I use Sunny 16 in each kind of photography?
What is the Sunny 16 rule?
Short answer. Sunny 16 lets you expose without a meter. On a bright day with distinct shadows, set the aperture to f/16 and the shutter speed to one over the ISO. At ISO 100 that gives f/16 at about 1/125, and at ISO 400 it gives f/16 at about 1/500.
- The rule is for a subject lit from the front, in the middle of the day, away from sunrise and sunset.
- Kodak’s own guide for Tri-X 400 film says f/16 at 1/500 for bright or hazy sun with distinct shadows. 1/500 is the dial speed nearest to 1/400, which is one over the ISO (Kodak, n.d.).
- It works because the sun is a steady light. Its brightness hardly changes from day to day.
- The rule gives a start. You still check the picture.
A simple picture to remember: the sun is the same size in the sky every day, so it gives the same exposure every day. Cloud, haze and shade are what change it. The next question shows how.
Cham tipMemorise one line: sun, f/16, one over the ISO. Everything else is a change from this.
Cham taskOn a sunny day, set f/16 and a shutter speed near one over your ISO. Take a picture and look at the histogram.
Check yourself: Your ISO is 200 on a sunny day. What are the Sunny 16 settings?
f/16 at about 1/200. The nearest dial speed is 1/250.
How does Sunny 16 change with the weather?
Short answer. Open the aperture one stop for each step the light softens. Kodak’s guide for Tri-X 400 runs from f/16 in bright sun with distinct shadows to f/11 in weak hazy sun, f/8 under bright cloud, and f/5.6 in heavy overcast or open shade, all at 1/500 (Kodak, n.d.).
- The more cloud, the softer the shadows, the more light you must let in.
- On bright sand or snow, close down one stop to f/22 (Kodak, n.d.).
- For a backlit close-up subject Kodak says to use f/8 at 1/500, which is two stops more light than f/16 (Kodak, n.d.).
- Keep the shutter speed at one over the ISO and move the aperture. Or change both and keep the product the same.
| Lighting | Aperture at 1/500 s | Change from f/16 |
|---|---|---|
| Bright or hazy sun on light sand or snow | f/22 | Close 1 stop |
| Bright or hazy sun, distinct shadows | f/16 | None |
| Weak, hazy sun, soft shadows | f/11 | Open 1 stop |
| Cloudy bright, no shadows | f/8 | Open 2 stops |
| Heavy overcast, open shade | f/5.6 | Open 3 stops |
Table 1. Kodak’s daylight guide for Tri-X 400 (ISO 400). Use it for average front-lit subjects from two hours after sunrise to two hours before sunset (Kodak, n.d.).
Cham tipLook at the shadow edge. Hard edge, f/16. Soft edge, f/11. Almost no edge, f/8. No shadow, f/5.6.
Cham taskShoot the same wall in sun, then when a cloud covers the sun. Open up by the number of stops in Table 1 and check the histogram.
Check yourself: The shadows are soft and the sky is a thin white cloud. Which aperture would you start with at 1/500 and ISO 400?
f/11. Soft shadows from a weak, hazy sun are one stop more light than f/16.
How do I use Sunny 16 with another ISO or shutter speed?
Short answer. Keep the total the same. Sunny 16 at any ISO is f/16 at one over the ISO. Any other pair that gives the same exposure works too: for each stop you open the aperture, make the shutter one stop faster.
- At ISO 100 the starting pair is f/16 at 1/125, and at ISO 400 it is f/16 at 1/500.
- For motion you may want a faster shutter. Then open the aperture to match.
- The table below lists the pairs for ISO 100 and ISO 400. Move one row down for each stop.
- The speed one over the ISO is a handy guess. Cameras have 1/125 and 1/250 and not 1/100 and 1/200, so use the nearest.
| Aperture | ISO 100 | ISO 400 |
|---|---|---|
| f/22 | 1/60 s | 1/250 s |
| f/16 | 1/125 s | 1/500 s |
| f/11 | 1/250 s | 1/1000 s |
| f/8 | 1/500 s | 1/2000 s |
| f/5.6 | 1/1000 s | 1/4000 s |
| f/4 | 1/2000 s | 1/8000 s |
Table 2. Sunny 16 pairs for bright sun. Each row is the same exposure. The ISO 400 column is two stops faster than the ISO 100 column.
Cham tipDo the stop count in your head: f/16 to f/8 is two stops, so 1/125 becomes 1/500.
Cham taskWrite the Sunny 16 pairs for ISO 200 and ISO 800 on a card. Check them in sun.
Check yourself: At ISO 100 you move from f/16 at 1/125 to f/5.6. What shutter speed keeps the exposure?
1/1000. f/16 to f/5.6 is three stops wider, so the shutter must be three stops faster.
What is exposure value (EV)?
Short answer. Exposure value is a single number that stands for a combination of aperture and shutter speed. It equals the base 2 logarithm of the f-number squared divided by the time, taken at ISO 100. Every pair that gives the same exposure has the same EV, and one EV step is one stop.
- EV = log2(N² ÷ t), where N is the f-number and t is the time in seconds.
- f/5.6 at 1/30 s: 31.36 times 30 is 940.8, and its base 2 logarithm is 9.9, so it is EV 10.
- f/8 at 1/250 s is EV 14. f/11 at 1/125 s is also EV 14. f/8 at 1/125 s is EV 13, one stop more exposure.
- A higher EV means a brighter scene and less exposure, so you use a faster shutter or a smaller aperture.
Why a single number? A pair like f/8 at 1/250 is two numbers, and it is hard to compare it with f/11 at 1/125. EV puts both on one line. Photographers use EV to talk about how bright a scene is and how much exposure it needs.
Präkel defines EV 0 as an exposure of one second at f/1 with ISO 100 sensitivity, and every higher EV number is one stop less light (Präkel, 2009).
| Aperture | Shutter speed | N² ÷ t | EV |
|---|---|---|---|
| f/22 | 1/60 s | 29,040 | 14.8 |
| f/16 | 1/125 s | 32,000 | 15.0 |
| f/11 | 1/250 s | 30,250 | 14.9 |
| f/8 | 1/500 s | 32,000 | 15.0 |
| f/5.6 | 1/1000 s | 31,360 | 14.9 |
| f/4 | 1/2000 s | 32,000 | 15.0 |
Table 3. Six pairs that all work out to EV 15. The small differences come from the rounded f-numbers and shutter speeds on a camera.
Cham tipDo not calculate. Learn EV 15 is sun, EV 13 is bright cloud and EV 10 is a dim room, and count stops from there.
Cham taskWork out the EV of f/5.6 at 1/125 and of f/8 at 1/60 with a calculator. Which one gets more light?
Check yourself: Is f/11 at 1/250 the same EV as f/8 at 1/500?
Yes, both are close to EV 15. f/11 to f/8 opens one stop, and 1/250 to 1/500 gives one stop less time.
How do I read an EV chart?
Short answer. An EV chart gives the exposure value for each pair of f-number and shutter speed at ISO 100. Find the shutter speed down the side and the f-number across the top, and the cell where they meet is the EV. All cells with the same number are equal exposures, so a single meter reading gives you the whole set of choices.
- Move one column to the right and the aperture closes one stop, so the EV goes up by one.
- Move one row down and the shutter is twice as fast, so the EV goes up by one.
- Cells on one diagonal share an EV. f/2.8 at 1/125 s, f/4 at 1/60 s and f/5.6 at 1/30 s are all EV 10.
- EV 0 is one second at f/1. The chart below starts at f/2, where 1 s reads 2, and Präkel’s wider chart shows the f/1 column.
Meter first, then choose. Say a meter reads EV 10. For a shallow depth of field you pick f/2.8, and the chart gives 1/125 s. To show motion with a slow shutter you might pick 1/2 s, and the chart then gives f/22. The light in the scene has not changed. You have only chosen a different split between the size of the opening and the time it stays open.
The chart is worked out for ISO 100. At another ISO, add the stops, as the chapter on ISO below shows.
Dark scenes are where meters give out first. In Präkel’s 2009 examples, a top camera meter at ISO 100 starts at EV 0 in evaluative mode and EV 2 in spot mode. A hand-held meter reads EV 1 to 24 in spot mode and EV 2 to 23 as an incident meter (Präkel, 2009). Newer gear may do better, so read your own manual. Lens speed sets a limit too: a slow lens passes less light, so it fails earlier in the dark.
| Shutter (s) | f/2 | f/2.8 | f/4 | f/5.6 | f/8 | f/11 | f/16 |
|---|---|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
| 1/2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |
| 1/4 | 4 | 5 | 6 | 7 | 8 | 9 | 10 |
| 1/8 | 5 | 6 | 7 | 8 | 9 | 10 | 11 |
| 1/15 | 6 | 7 | 8 | 9 | 10 | 11 | 12 |
| 1/30 | 7 | 8 | 9 | 10 | 11 | 12 | 13 |
| 1/60 | 8 | 9 | 10 | 11 | 12 | 13 | 14 |
| 1/125 | 9 | 10 | 11 | 12 | 13 | 14 | 15 |
| 1/250 | 10 | 11 | 12 | 13 | 14 | 15 | 16 |
| 1/500 | 11 | 12 | 13 | 14 | 15 | 16 | 17 |
| 1/1000 | 12 | 13 | 14 | 15 | 16 | 17 | 18 |
| 1/2000 | 13 | 14 | 15 | 16 | 17 | 18 | 19 |
| 1/4000 | 14 | 15 | 16 | 17 | 18 | 19 | 20 |
| 1/8000 | 15 | 16 | 17 | 18 | 19 | 20 | 21 |
Table 4. EV chart for ISO 100, from f/2 to f/16 and from 1 s to 1/8000 s. Worked out from EV = log2(N² ÷ t) and checked against Präkel’s wider chart, which runs from f/1 to f/64 and from 60 s to 1/8000 s (Präkel, 2009). Shutter speeds are the rounded numbers on the camera dial.
Cham tipFind the meter reading in the chart, then slide along the diagonal to the pair you want.
Cham taskA meter reads EV 11. Write down three pairs from the chart that give EV 11. Shoot one of them and check the brightness.
Check yourself: A meter reads EV 13. You choose f/8. What shutter speed does the chart give?
1/125 s. In the f/8 column, 1/125 s reads 13.
What EV numbers match common light?
Short answer. At ISO 100 a home lit by lamps is about EV 5 to 7, an overcast day is EV 10 to 12, and full sun with hard shadows is EV 15 to 16. Treat these ranges as a guide, because real light varies, and let your meter give the true number for the scene in front of you (Präkel, 2009).
- Indoor light is dim. A room with lamps sits around EV 5 to 7, and a well lit office around EV 7 to 8 (Präkel, 2009).
- Daylight outdoors runs high: bright cloud is EV 13, hazy sun EV 14, and full sun with hard shadows EV 15 to 16 (Präkel, 2009).
- Very bright things go further. A white object in full sun is near EV 17, and a glint of sun off a surface near EV 18 (Präkel, 2009).
- Ranges overlap, because dusk and an overcast day both reach EV 10 to 12. Treat the table as a starting point.
The list helps you guess the light before you lift the camera. If your guess says EV 15 and the meter says EV 12, check the ISO and the metering mode before you trust either number.
The numbers match the Sunny 16 ladder in the chapter on EV 15. Full sun with hard shadows is EV 15, and each weaker kind of light is one step lower.
| Light | EV at ISO 100 | Example pair |
|---|---|---|
| Night: bright moonlight (full moon) | −2 to −5 | f/2 at 30 s |
| Indoors: a home lit by lamps | 5 to 7 | f/2 at 1/15 |
| Indoors: a well lit office | 7 to 8 | f/2.8 at 1/30 |
| Evening: a bright street at night | 8 | f/2 at 1/60 |
| Evening: the lit floor of a sports arena | 8 to 9 | f/2.8 at 1/60 |
| Evening: dusk | 9 to 12 | f/4 at 1/60 |
| Daytime: an overcast sky | 10 to 12 | f/5.6 at 1/125 |
| Daytime: bright cloud, no shadows | 13 | f/8 at 1/125 |
| Daytime: hazy sun, soft shadows | 14 | f/8 at 1/250 |
| Daytime: full sun, hard shadows | 15 to 16 | f/16 at 1/125 |
| Very bright: a white object in full sun | 17 | f/16 at 1/500 |
| Very bright: sun glinting off a surface | 18 | f/16 at 1/1000 |
Table 5. Common light at ISO 100, grouped by place and time of day. The EV ranges follow Präkel’s list (Präkel, 2009). The example pairs are worked out here from the EV chart, using one EV inside each range. For the full moon, Präkel’s table prints EV 5, but his text on night photography gives bright moonlight as −2 to −5 EV. Moonlight is far dimmer than a lit room, so the table value looks like a lost minus sign, and we use the range from his text.
Cham tipLearn three anchors: EV 15 for sun with hard shadows, EV 12 for overcast, and EV 7 for a lit room.
Cham taskPick five places today: a window, a room, a street in shade, the open sky and a bright wall. Guess each EV from the table, then check with a meter or a phone app.
Check yourself: Which is brighter, hazy sun with soft shadows or bright cloud with no shadows, and by how much?
Hazy sun. It is EV 14 against EV 13, so it is one stop brighter.
How does ISO change EV?
Short answer. EV is worked out at ISO 100. When you raise the ISO, the settings need a higher EV for the same picture, one step of EV for each doubling of ISO. The scene has not become brighter. The sensor has become more sensitive, so the settings moved.
- The formula is EV at ISO S = EV at ISO 100 + log2(S ÷ 100).
- ISO 200 adds 1. ISO 400 adds 2. ISO 800 adds 3.
- The same settings at a higher ISO give a brighter picture. For the correct brightness you add stops of EV with the aperture or the shutter.
- Example: f/11 at 1/500 is EV 16 at ISO 100. At ISO 800 the correct settings are EV 19, for example f/16 at 1/2000 or f/22 at 1/1000.
| ISO | f/5.6 at 1/30 s gives a picture that is | Settings for a correct picture |
|---|---|---|
| 100 | correct | EV 10, f/5.6 at 1/30 s |
| 200 | 1 stop too bright | EV 11, f/8 at 1/30 s |
| 400 | 2 stops too bright | EV 12, f/11 at 1/30 s |
| 800 | 3 stops too bright | EV 13, f/16 at 1/30 s |
Table 6. One scene, four ISOs. The scene is EV 10 at ISO 100 and does not change. The EV of the settings goes up by one stop each time the ISO doubles.
Cham tipAdd two stops of EV for every two doublings of the ISO. It keeps the picture the same.
Cham taskShoot a grey wall at f/5.6 and 1/30 at ISO 100, 200, 400 and 800. Then change the aperture to keep the brightness the same. Write the EV of the settings each time.
Check yourself: At ISO 100 the settings are EV 12. What EV do you need at ISO 400 for the same picture?
EV 14. ISO 400 is two doublings from ISO 100, so add two.
How is Sunny 16 linked to EV 15?
Short answer. Sunny 16 is EV 15. At ISO 100, f/16 at 1/125 s works out to EV 15, and each weather step in Sunny 16 is one EV lower: f/11 is EV 14, f/8 is EV 13 and f/5.6 is EV 12.
- f/16 at 1/125 s: 256 times 125 is 32,000, and log2 of that is 14.97, so EV 15.
- Kodak’s table is for ISO 400 at 1/500 s. In the settings that is EV 17. ISO 400 is two stops above ISO 100, so the scene itself is EV 15 (Kodak, n.d.).
- So a scene in sun with distinct shadows is EV 15, weak hazy sun EV 14, cloudy bright EV 13 and heavy overcast EV 12.
- Sand or snow in bright sun is EV 16, one stop brighter.
Cham tipRemember two anchors: EV 15 for sun with hard shadows, and EV 12 for a heavy overcast day.
Cham taskLook at the sky today. Pick the EV from Figure 2. Then check it with a meter or a test picture.
Check yourself: The scene is EV 13 at ISO 100. Which Sunny 16 weather is that?
Cloudy bright, with no shadows. In Kodak’s table that is f/8 at 1/500 for ISO 400.
What is light value (LV)?
Short answer. Light value is a number that says how bright the scene is, on the same one-stop scale as EV. LV describes the light and EV describes the camera settings. A scene of LV 15 is bright sun, and a camera at ISO 100 exposes it correctly at EV 15.
- In short, LV is how bright the subject is, and EV is the exposure setting on the camera.
- The ISO does not change LV. The scene stays the same.
- The ISO does change the EV of the settings: EV of the settings = LV + log2(ISO ÷ 100).
- Books and apps do not always use the same words. Some use the same name for both numbers, so check the definition before you read a table.
Some tables call the last row of the ISO table LV. Strictly it is the EV of the settings that give a correct picture. The scene’s own LV is 10 in that example, and it stays at 10 for every ISO. This guide keeps the two words separate: LV for the light, EV for the camera settings.
Präkel traces light value numbers to Ansel Adams’s Zone System articles of 1948, and says EV added film speed to the same idea (Präkel, 2009).
Cham tipLV is about the light. EV is about the camera. If ISO changes the number, it is EV.
Cham taskTake a scene at LV 10 (a dim room). Write the EV of the settings you need at ISO 100, 400 and 1600.
Check yourself: You change from ISO 100 to ISO 1600 in the same room. Does the LV of the room change?
No. The room has not changed. The EV of the settings you need goes up by four stops, because 1600 is four doublings of 100.
What is the difference between EV 15 and +1 EV compensation?
Short answer. EV 15 describes the light, or a pair of settings. The +1 EV on your camera dial is a different thing, an instruction: it asks for one stop more exposure than the meter chose. The numbers run in opposite directions. A higher EV number means a brighter scene and less exposure, while a higher compensation number means a brighter picture.
- Absolute EV, like EV 15, is a fixed number on the scale. It is worked out at ISO 100.
- Relative EV, like +1 or −2, is a change from the meter reading. +1 EV is one stop brighter and −2 EV is two stops darker.
- Sony’s help guide says a plus setting makes the picture brighter and a minus setting makes it darker (Sony, n.d.).
- So use compensation for a picture that is too dark or too bright. Use EV numbers to compare scenes and settings.
| Term | Example | What it tells you | Higher number means |
|---|---|---|---|
| Absolute EV | EV 15 | How bright the scene is, or which settings match it at ISO 100 | Brighter scene, less exposure |
| Relative EV (compensation) | +1 EV | A change from the meter reading | More exposure, brighter picture |
Table 7. Two uses of the letters EV.
Cham tipIf the number is signed (+1, −2) it is a change. If it is plain (EV 15) it is a level.
Cham taskShoot a white wall with the meter reading, then at +1 and +2. Write which looks white.
Check yourself: Your meter says EV 12 now and EV 14 after the sun comes out. Did the scene get brighter or darker?
Brighter, by two stops. A higher scene EV means more light.
How can I practise Sunny 16 and EV?
Short answer. Guess first, then check. Go out on a day with changing light, write down the settings Sunny 16 gives, take the picture, and compare with the meter. Your log will show how many stops you were off.
- Use a day with sun and cloud. Do at least five scenes: sun, hazy sun, cloud, shade and a window.
- For each scene write your guess in the log before you look at the meter.
- Then check the camera meter and write the difference in stops.
- After a week your guesses will be within one stop.
| Scene | My Sunny 16 guess | The meter says | Stops off |
|---|---|---|---|
Table 8. Practice log. Copy this into your notebook.
Cham tipDo the guess before you look at the meter. A guess after looking is not practice.
Cham taskDo the five-scene round today and fill in the log.
Check yourself: Why write your guess before looking at the meter?
The aim is to learn to read the light. If you look first, you copy the meter and you do not learn.
How do I use Sunny 16 in each kind of photography?
Short answer. Sunny 16 gives a starting exposure for bright sun: f/16 at one over the ISO. For each stop you open the aperture, make the shutter one stop faster. The lines below are worked from that rule for a front-lit subject. Check the picture and adjust.
- Birds. f/8, ISO 400, 1/1600 s.
- Animals and pets. f/5.6, ISO 200, 1/1600 s.
- Reptiles. f/8, ISO 100, 1/400 s.
- Insects and macro. Without flash, f/11, ISO 200, 1/400 s.
- Portraits. f/4, ISO 100, 1/1600 s. In open shade, open one stop.
- Fashion. f/2.8, ISO 100, 1/3200 s. If your camera cannot go that fast, add an ND filter.
- Wedding and events. Outdoor ceremony: f/8, ISO 200, 1/800 s. In open shade, open one stop.
- Automotive. Parked car: f/8, ISO 100, 1/400 s. For a panning blur at 1/60 s, add an ND filter.
- Photojournalism. f/8, ISO 200, 1/800 s.
- Sports and action. f/4, ISO 100, 1/1600 s.
- Landscape. f/16, ISO 100, 1/125 s on a bright day. Open one stop for each step the light softens.
- Street and documentary. f/11, ISO 400, 1/800 s.
- Night and astro. The moon is lit by the sun, so f/11 at one over the ISO exposes a full moon. This is called the Looney 11 rule.
- Cinema. A sunny exterior is about EV 15 at ISO 100. With a 180 degree shutter, ND filters are needed even at f/16.
Questions beginners ask
What is the Sunny 16 rule?
On a sunny day with distinct shadows, set f/16 and a shutter speed of one over your ISO. At ISO 100 that is f/16 at about 1/125.
What aperture should I use under cloud?
Open the aperture one stop for each step. Kodak’s guide goes f/16 in sun, f/11 in weak sun, f/8 under bright cloud and f/5.6 in heavy overcast or shade.
What is EV 15?
It is the exposure of f/16 at 1/125 and ISO 100, or any equal pair. It matches a sunny scene with distinct shadows.
What is the difference between EV and LV?
LV describes how bright the scene is. EV describes the exposure settings. A higher ISO raises the EV you need, but the scene’s LV stays the same.
Does ISO change EV?
Yes, in the settings. Each doubling of the ISO adds one stop of EV, so ISO 400 adds two stops to the EV you need at ISO 100.
What does an EV chart show?
An EV chart shows the exposure value for each pair of f-number and shutter speed at ISO 100. Every cell with the same number is an equal exposure. A meter reading of EV 10, for example, gives f/2.8 at 1/125 s, f/4 at 1/60 s or f/5.6 at 1/30 s.
References
- Kodak. (n.d.) Kodak Professional Tri-X 320 and 400 Film. Data sheet F-4017, Daylight Exposure Guide. kodakprofessional.com/sites/default/files/wysiwyg/film/f4017_trix_320400.pdf
- Präkel, D. (2009) Basics Photography 07: Exposure. Lausanne: AVA Publishing. See the section on Exposure Value (pp. 30–31).
- Sony. (n.d.) Exposure Comp. ZV-E10 Help Guide. helpguide.sony.net/ilc/2070/v1/en/contents/TP0001140445.html
How to cite this guide. Alex, A., & Joseph, A. (2026). The Sunny 16 rule and exposure value: A guide for photographers and cinematographers. Creative Hut Academy. https://creativehut.org/library/sunny-16-rule-and-exposure-value/
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