By Matteo Martignago, cinematographer and colorist. Updated July 2026.
What is the Sunny 16 rule?
The Sunny 16 rule is a way to estimate correct daylight exposure without a light meter. On a clear, sunny day with your subject front lit, set the aperture to f/16 and the shutter speed to the reciprocal of your ISO, so ISO 100 gives 1/100 second, or 1/125 on most cameras.
From that one anchor you can read the light in almost any daytime scene. It works because bright, direct sunlight is consistent: the sun does not care what camera you own, so a clear midday sky delivers close to the same amount of light everywhere on Earth. The rule bottles that constant into a setting you can dial in from memory. Below you get the full chart, the shutter and ISO tables, the physics behind the number, and two things most guides skip: how to carry the rule into video and how a consistent exposure pays off later in the grade.
The Sunny 16 chart
The whole Sunny 16 chart fits on one card (some shooters spell it the Sunny Sixteen chart). Keep the shutter at the reciprocal of your ISO, and change the aperture as the light changes. That single habit, hold the shutter and move the aperture, is the part beginners most often get backwards.
And the same ladder as a plain table you can scan or copy:
| Lighting condition | Aperture | Shutter speed (ISO 100) | Shadows |
|---|---|---|---|
| Snow, sand, or bright beach | f/22 | 1/125 s | Dark, hard edged |
| Bright sun (Sunny 16) | f/16 | 1/125 s | Distinct, hard edged |
| Hazy sun or light cloud | f/11 | 1/125 s | Soft edged |
| Overcast | f/8 | 1/125 s | Barely visible |
| Heavy overcast | f/5.6 | 1/125 s | None |
| Open shade or sunset | f/4 | 1/125 s | None; add +1 stop for backlight |
If you shoot at a different ISO, keep the same apertures and move the shutter to match the reciprocal of that ISO. The next section spells that out.
Why f/16? The physics of bright sun
The number is not arbitrary. Photographers measure light in exposure values, or EV, and bright, direct, front-lit sunlight sits at EV 15 at ISO 100. Feed EV 15 into the exposure equation at ISO 100, and f/16 falls out with a shutter near 1/125 second. Different f-stop and shutter pairs can hit the same EV 15, but f/16 with 1/ISO is the pair that is easiest to remember and gives a deep depth of field for landscapes and street work.
The deeper reason the rule is trustworthy is that it is built on incident light, the light falling on the scene, rather than reflected light bouncing off your subject. Your camera’s built-in meter reads reflected light and tries to render whatever it sees as middle gray, which is why it underexposes a snowfield and overexposes a black cat. Sunny 16 sidesteps that error entirely, because it estimates the light coming from the sky, not the tone of the thing in front of you. Learn it and you also learn to read your camera’s meter with a skeptical eye. It is the same instinct behind the exposure triangle: once you understand how aperture, shutter, and ISO trade off, a single anchor point is all you need.
Shutter speed and ISO: the reciprocal rule
At f/16 in bright sun, the shutter speed is 1 divided by your ISO. Change the ISO and the shutter tracks it. One wrinkle: older cameras do not offer a 1/100, 1/200, or 1/400 marking, so ISO 100, 200, and 400 round to the nearest real speed of 1/125, 1/250, and 1/500. Many modern cameras give you the exact values too. Either is within the tolerance of the rule, a fraction of a stop.
| ISO | Shutter at f/16 (nearest marked) | Exact 1 / ISO |
|---|---|---|
| 25 | 1/30 s | 1/25 s |
| 50 | 1/60 s | 1/50 s |
| 100 | 1/125 s | 1/100 s |
| 200 | 1/250 s | 1/200 s |
| 400 | 1/500 s | 1/400 s |
| 800 | 1/1000 s | 1/800 s |
Read the shadows, not the weather report
“Sunny” and “overcast” are vague. A faster, more reliable way to place yourself on the chart is to look at the shadows your subject casts:
- Hard, dark, sharp edged shadows mean full sun. Shoot f/16 (or f/22 if snow or bright sand is bouncing extra light around).
- Soft edged shadows with a visible but gentle edge mean hazy sun or light cloud. Open to f/11.
- Shadows you can barely find mean a solid overcast. Open to f/8.
- No shadow at all, flat and even light, means heavy cloud or open shade. Open to f/5.6 or f/4.
Shadows are the honest report. They tell you how much of the sun is actually reaching your subject, which is the only thing the rule cares about. This is also why Sunny 16 is a daytime, front-lit rule: once the sun drops low and rakes across your scene at sunset or golden hour, the shadows lengthen and the math no longer holds. More on that failure case below.
Equivalent exposures: same light, shallower depth of field
f/16 is only the starting point. Any scene has a whole row of settings that let in exactly the same amount of light, because every stop you open the aperture is canceled by a stop of faster shutter. This is the single most misremembered part of the rule: opening up means a quicker shutter, never a slower one. Slowing the shutter while you open the aperture doubles the light at every step and blows the frame out.
| Aperture | Shutter (ISO 100, bright sun) | Reach for it when |
|---|---|---|
| f/22 | 1/60 s | Maximum depth of field (watch for diffraction softening) |
| f/16 | 1/125 s | The Sunny 16 baseline, landscapes and groups |
| f/11 | 1/250 s | Deep scenes with a little more sharpness margin |
| f/8 | 1/500 s | General shooting, the classic sharp aperture |
| f/5.6 | 1/1000 s | Starting to separate a subject from the background |
| f/4 | 1/2000 s | Shallow depth of field portraits in full sun |
| f/2.8 | 1/4000 s | Very shallow; you may run out of shutter and need ND |
Notice the bottom of the ladder. To shoot a portrait wide open at f/2.8 in bright sun, you would need 1/4000 second, and many cameras top out there or a stop beyond. Push wider, or shoot video where your shutter is locked, and you run out of shutter speed. A neutral density filter solves it: it is sunglasses for your lens, subtracting a set number of stops so you can hold a wide aperture without overexposing. Sunny 16 tells you exactly how many stops of ND you need.
The Sunny 16 rule for video and cinematography
For filmmakers, the rule matters more, because one of your three exposure controls is taken away from you. To get natural-looking motion blur, you lock the shutter to roughly double your frame rate, the 180 degree shutter angle. At 24 frames per second that means a 1/50 second shutter, and you leave it there. You cannot trade shutter for aperture the way a stills shooter does.
So the video version of Sunny 16 becomes: lock the shutter at 1/50, keep ISO at base, and read the aperture off the light. Here the filmmaker hits a wall the stills shooter never does. At 1/50 in bright sun, correct exposure is already about f/22, roughly a stop and a third smaller than f/16, and f/22 softens most lenses through diffraction. So daylight video almost always calls for the ND filters from the last section, and Sunny 16 tells you how many stops to dial in. Want a shallow, cinematic f/2.8 in full sun at 1/50 and base ISO 100? You are about six stops over correct exposure, so you reach for roughly six stops of ND (an ND 1.8), and a camera with a higher base ISO needs even more. One last wrinkle: cinema lenses are marked in T-stops rather than f-stops. A T-stop is an f-stop corrected for the light a lens actually transmits, so a T22 gives you the true exposure while an f/22 marking on a cheaper lens sits a touch darker. In practice the rule stops being a way to guess settings and becomes a way to calculate the filter you need.
Expose for the grade: a colorist’s take
Even with a good meter in the bag, I still lean on Sunny 16, and the payoff shows up later, in the grade. When you grade footage or a set of photos, inconsistency is what eats your time. Let a reflective meter set each shot on a sunny afternoon and it reacts to whatever fills the frame, a dark jacket here, a bright wall there, so the clips arrive on the timeline at slightly different brightnesses and matching them is slow work. Exposures built on an incident anchor like Sunny 16 arrive already consistent, because they were all keyed to the same sunlight rather than to the subject. They cut together more cleanly, and matching them in color grading software goes faster.
The second payoff is highlight protection. A correct Sunny 16 exposure keeps a bright sky and skin tones comfortably below clipping, which leaves you room to shape them later. Blown highlights are the one thing a grade cannot recover; there is no detail in a clipped white to bring back. A shadow that is a touch dark can be lifted, but a sky that hit pure white is gone. Nailing a repeatable base exposure in camera is what gives the grade something to work with, and it is why an old film-era rule of thumb still earns its place in a modern grading workflow, right alongside tools like the offset control in DaVinci Resolve.
Using Sunny 16 on a modern mirrorless camera
You are not throwing away your meter. On a modern camera, Sunny 16 becomes a fast sanity check and a set of habits that make the meter more trustworthy:
- Shoot at base ISO. Sunny 16 assumes your camera’s native sensitivity, usually ISO 100, sometimes 64 or 200. Base ISO also gives you the most dynamic range and the cleanest file, so it is where you want to be in bright light anyway.
- Trust the histogram over the screen. The brightness of your rear LCD lies, especially outdoors where the sun washes it out. The histogram does not. Aim for a spread of tones without a spike jammed against the right edge.
- Turn on the highlight alert. The blinking “blinkies” on overexposed areas tell you the moment a sky or a specular highlight clips. Back off until only true speculars, like the sun glinting off chrome, are flashing.
- Use it to catch the meter’s mistakes. When your meter suggests something wildly different from Sunny 16 in obvious bright sun, it is usually the meter being fooled by a snowfield, a backlight, or a spotlight, not the rule being wrong. Sunny 16 is the second opinion.
Once you trust your histogram, some shooters deliberately expose a touch brighter than the Sunny 16 baseline when working in raw, as long as no important highlight clips, then pull it back in post for a cleaner file. That is the “expose to the right” technique, and it is an optional refinement on top of Sunny 16, not a replacement for it.
When Sunny 16 is wrong, and the exact stops to fix it
The rule assumes a specific situation: a front-lit subject in direct, roughly midday sun, from about two hours after sunrise to two hours before sunset. Step outside those assumptions and you adjust, or set it aside:
| Situation | What goes wrong | The fix |
|---|---|---|
| Backlit subject | The sun is behind your subject, so their face falls into shadow | Open +1 stop, or meter for the face and let the background go bright |
| Snow or white sand | Sunny 16 itself is correct, but a reflective meter underexposes the scene to gray | Trust Sunny 16 (f/22 in full sun), or add +1 stop if you are following the meter |
| Golden hour or low sun | The rule assumes high, direct sun; low raking light is far dimmer | Sunny 16 does not apply. Meter the scene or bracket your exposures |
| Long telephoto or heavy haze | Distant, hazy air and long lenses lose a little light | Add roughly +1 stop |
| Fast-moving subject | 1/125 second is too slow to freeze fast action | Open the aperture for an equivalent faster shutter, for example f/8 at 1/500 |
| Deep shade under trees | Several stops darker than open shade | Drop to f/4 and beyond, or raise ISO; the rule has run out |
One caveat worth its own line: reaching for f/22 in snow works, but f/22 softens most lenses through diffraction. If you can, shed that extra stop of light with a faster shutter or a lower ISO instead of closing all the way down, and keep your aperture in the sharp f/8 to f/11 range.
The sunny rule family: Looney 11 and Moony 8
Sunny 16 has siblings for the night sky, built on the same incident logic. The full moon is lit by the same direct sunlight as a daytime landscape, just seen from a great distance, so its sunlit surface follows the Looney 11 rule: set f/11 and keep the shutter at the reciprocal of your ISO. A softer or hazier moon drops you to the Moony 8 rule, f/8 at 1/ISO. These only expose the moon’s bright surface correctly, not a dark foreground, which is why moon photographs so often blend two exposures. Do not confuse Looney 11 with Sunny 16, and never call the base rule “Sunny 11.” Sunny is 16; the moon is 11.
Sunny 16 rule FAQ
Does the Sunny 16 rule work with digital cameras?
Yes. The rule describes sunlight, not film, so it applies to any camera. On digital it is even easier to use, because you can confirm the result instantly on the histogram and adjust ISO on the fly. Most photographers use it as a sanity check against the built-in meter rather than as a full replacement.
What shutter speed do you use for Sunny 16 at ISO 400?
At f/16 in bright sun, ISO 400 calls for 1/400 second, which rounds to 1/500 on cameras that lack a 1/400 marking. Both are correct within the tolerance of the rule.
What aperture do you use on a cloudy or overcast day?
Open up from f/16. Hazy sun or light cloud is about f/11, a solid overcast is f/8, and a heavy, dark overcast is f/5.6, all while keeping the shutter at the reciprocal of your ISO. Judge it by how soft the shadows are.
Is the Sunny 16 rule accurate?
It is accurate enough to expose a frame well, and it was never meant to be precise to the third of a stop. It gets you within tolerance of a correct exposure, which is plenty for a rule you can use with no meter at all. For raw shooters, that margin is easy to fine-tune in post.
How do you expose film without a light meter?
Sunny 16 is exactly how generations of photographers did it. Set your aperture by the light using the chart above, set the shutter to the reciprocal of the film’s ISO, and you will get usable negatives across a sunny day. Negative film is forgiving of a little overexposure, so err bright if you are unsure, especially with a simple point-and-shoot film camera that has no meter.
Do professional photographers still use the Sunny 16 rule?
Many do, not as their primary exposure method but as a mental baseline and a check. Knowing that a sunny scene is f/16 at 1/ISO lets you spot a bad meter reading in a second, set a manual flash by hand, or expose a drone shot you cannot chimp. It is one of those fundamentals that makes everything else faster.
The bottom line
The Sunny 16 rule is daylight exposure reduced to one setting you can carry in your head: f/16 at 1 over your ISO in bright sun, then open the aperture one stop for each step the light drops. Learn the chart, read your shadows instead of the forecast, and you will expose confidently in daylight with or without a meter. Carry it into video and it hands you your ND filter math; carry it into the grade and it hands you consistent, protected exposures that cut and match cleanly.
