Shutter Priority Mode: What It Is and When to Use It

Shutter priority mode (S on most mode dials, Tv on some) lets you choose the shutter speed while the camera chooses the aperture that gives a correct exposure. It is the mode for pictures where the look of motion matters most: 1/1000 second or faster to freeze sport and birds, 1/30 to 1/60 to pan with a passing car, a quarter second or longer to smooth flowing water.

Before you pick a mode, decide what the picture needs most. If it is frozen or blurred motion, the shutter speed is the setting to fix, and shutter priority fixes it for you while the light changes. If it is a soft background or front to back sharpness, the aperture comes first, and aperture priority mode is the better tool.

Want to try those speeds on a moving subject now? The camera simulator has a Shutter mode, and a surfer to freeze, blur or pan with.

How shutter priority divides the work (S or Tv on the dial)

Turn the mode dial to S or Tv (“time value”). On cameras with no mode dial, the same mode is reached by setting the aperture ring or aperture control to its automatic (A) position and choosing a speed on the shutter dial. Either way the split is the same:

• You set the shutter speed with the main command dial, usually in one-third stop steps (1/250, 1/320, 1/400, 1/500 and so on).
• The camera sets the aperture. It meters the scene and opens or closes the lens until the exposure matches what the meter wants.
• You or the camera set the ISO. With a fixed ISO, the aperture is the only thing the camera can move. With Auto ISO, it can move two things.

Half-press the shutter button and the aperture the camera has chosen appears beside your shutter speed in the viewfinder or on the screen. Read it every time. It tells you how much depth of field you are about to get, and how close the camera is to running out of adjustment.

Many viewfinders show only the bottom of the fraction, so “125” means 1/125 second and “1000” means 1/1000. Speeds of a second or longer are marked with a double prime: 0″5 is half a second, 2″ is two seconds, 15″ is fifteen seconds. Misreading “4” (1/4 second) as 4″ (four seconds) is easy until you know the mark.

The speeds on offer usually run from 30 seconds to the camera’s fastest speed. Exposures longer than 30 seconds are not available in shutter priority on most cameras; those need bulb mode or a timed long exposure setting.

The aperture range is your exposure budget

This is the part most explanations skip, and it explains nearly every problem people have with the mode. A camera’s shutter speeds span about 18 stops, from 30 seconds to 1/8000. A lens’s apertures do not. A zoom that runs from f/4 to f/22 has five stops of adjustment (f/4, f/5.6, f/8, f/11, f/16, f/22). A lens that opens to f/1.8 and closes to f/16 has a little over six.

In aperture priority the camera has 18 stops of speed to balance any aperture you pick, so it almost never runs out. In shutter priority at a fixed ISO it has five or six stops of aperture. Step outside that window and the picture comes out too dark or too bright.

The sunny 16 rule shows where the window sits. In full sun at ISO 100, a correct exposure is about 1/100 second at f/16. Every time you halve the shutter time, the aperture must open one stop: 1/200 at f/11, 1/400 at f/8, 1/800 at f/5.6, 1/1600 at f/4, 1/3200 at f/2.8. Move into open shade, about three stops darker, and every aperture in that list must open three stops more.

Read the chart across. In full sun, an f/4 to f/22 lens at ISO 100 can expose anything from 1/1600 to 1/50 correctly. Ask for 1/3200 and the frame is a stop too dark; ask for 1/25 and it is a stop too bright. In shade the whole window slides toward slow speeds: the same lens tops out at 1/200, which is too slow for most action. That is why action photographers raise the ISO long before the light looks dim. Each stop of ISO slides the window one stop toward faster speeds.

Zoom lenses that lose light as you zoom

Many zooms, including most kit lenses, are variable-aperture designs: f/3.5 at the wide end and f/5.6 at the long end, for example. Zooming in shrinks the widest aperture by about one and a third stops, and the budget shrinks with it. In open shade at ISO 100 such a lens can hold about 1/250 at its widest setting. Zoom to the long end and the fastest correct speed drops to about 1/100, without you touching the shutter dial. If the aperture starts blinking the moment you zoom in, this is why.

What happens when the budget runs out

On most cameras, the shutter fires anyway. The camera uses the widest or smallest aperture it has and records a frame that is too dark or too bright, warning you only with a blinking or highlighted aperture number. Some cameras offer an option often called safety shift. With it switched on, the camera quietly changes the shutter speed (or on some models the ISO) to rescue the exposure. That saves the frame, but it also means the speed you chose is no longer guaranteed. If you are relying on an exact speed for a pan or a water blur, check whether safety shift is on.

Shutter speeds to dial in for common subjects

The right speed depends on how fast the subject crosses the frame, not only on how fast it moves. A runner filling the frame needs a faster speed than the same runner small in a wide scene, and movement across the frame needs a faster speed than movement toward the camera. Treat these as starting points and check the result at full magnification on the rear screen.

The surfer at the top of this page shows the frame-filling point. At 1/250 the figure is sharp because it is small in a wide view of the wave. Fill the frame with the same rider on a longer lens and 1/250 would show blur in the arms and the spray; 1/1000 or faster would be the safer choice.

The train photo makes the same point from the other side. Everything outside the windows passes at the same train speed, yet at 1/80 the near rails and fields smear while the distant trees barely move. Nearby objects cross more of the frame in the same time. Distance and focal length change the speed you need as much as the subject’s own speed does.

Shutter priority also makes partial blur repeatable. Set one or two stops slower than the speed that freezes the subject (1/125 for someone walking briskly, say) and you get a sharp body with softened hands and feet, a hint of movement that a frozen frame lacks. Because the mode holds the speed while the light changes, the blur changes only when the movement does, not when a cloud passes. The guides to freezing motion and motion blur explain the two directions in depth, and camera settings for sports breaks the fast end down sport by sport.

Want to see how the speed, the subject’s pace and its distance trade against each other before you go out? The freeze or blur tool on the motion blur page lets you slide each one and watch the result.

The blinking aperture warning and how to clear it

When the speed you have chosen needs an aperture the lens does not have, the camera tells you, but quietly. Depending on the camera, the aperture number blinks, changes color, or is replaced by a short warning such as “Lo” or “Hi”. Keep adjusting until it stops.

• The widest aperture (for example f/4) blinks, or a low-light warning shows: What it means: Not enough light for this speed. The lens is wide open and the frame will be underexposed. Fix, in order of preference: Raise the ISO or turn on Auto ISO; choose a slower speed if the subject allows; zoom out if the lens loses light at the long end; use a faster lens.
• The smallest aperture (for example f/22) blinks, or a high-light warning shows: What it means: Too much light for this speed. The lens is fully stopped down and the frame will be overexposed. Fix, in order of preference: Lower the ISO to its base value; fit a neutral density filter; choose a faster speed; wait for softer light.
• No warning, but the aperture shown is f/16 or smaller: What it means: The exposure is correct, but fine detail starts to soften from diffraction, more so on smaller sensors, and sensor dust shows in skies. Fix, in order of preference: Lower the ISO, or add a neutral density filter so the camera can use f/8 to f/11.

Try it in the camera simulator: switch to Shutter priority, pick 1/1000 or faster for the moving subject and let the camera choose the aperture. When the aperture runs out, use the fixes in the table to get a good exposure.

The slow-speed case catches people most often. Suppose you want 1/15 second to blur a waterfall at midday. Counting from 1/100 at f/16, 1/15 is about 2.7 stops more time, so at ISO 100 in full sun it needs an aperture near f/40. The lens stops at f/22, so the camera overexposes by about a stop and two thirds and blinks f/22 at you. No setting on the camera fixes this. You need less light reaching the sensor: a three-stop neutral density filter brings the aperture back to about f/14, and a six-stop filter to about f/5. Deep shade or a darker time of day does the same job for free.

Need to know exactly what speed a given filter allows? The ND filter exposure calculator does the arithmetic for any filter strength.

Shutter priority with Auto ISO, exposure compensation and flash

Turn on Auto ISO and shutter priority becomes far more forgiving, because the camera now has a second control to work with. The usual behavior in falling light is that the camera opens the aperture until the lens is wide open, then raises the ISO to hold the exposure. Some cameras start raising the ISO a little before the lens is fully open. Either way, in dim light you get your chosen speed, the lens at or near its widest aperture, and whatever ISO it takes.

• The minimum shutter speed setting does nothing here. That Auto ISO option stops the camera choosing a slow speed in modes where the camera chooses the speed. In shutter priority you have already chosen it.
• The maximum ISO ceiling still applies. When the lens is wide open and the ISO hits the ceiling, the camera is out of options again and the underexposure warning returns. Decide which you would rather have: a slower speed, a higher ceiling, or a darker frame to lift later.
• You no longer control depth of field at all. In dim light the lens will sit wide open. With an f/1.8 lens and a close subject, that can leave only part of a face in focus. If that matters, manual exposure with Auto ISO (compared below) is the better tool.

Exposure compensation changes the aperture

The meter can be fooled in shutter priority exactly as in any other automatic mode, and the fix is the same control. Dial in +1 and the camera opens the aperture one stop; dial in -1 and it closes one stop. With Auto ISO on, the camera may change the ISO instead of, or as well as, the aperture. The full method, with starting values for snow, backlight and night scenes, is in the guide to exposure compensation.

One trap is specific to this mode. If the widest aperture is already blinking at a fixed ISO, positive compensation does nothing: the camera cannot open a lens that is already open. The picture stays dark until you raise the ISO or slow the shutter.

Flash limits the speeds you can choose

With a flash switched on, most cameras will not let you set a speed faster than the flash sync speed, typically somewhere between 1/160 and 1/250. Going faster requires high-speed sync, where the flash and camera support it.

Shutter priority on a phone

Most phone “pro” or manual modes let you set the shutter speed, but most phone lenses have a fixed aperture. There is nothing for the camera to open or close, so every change of speed is balanced by ISO alone. The budget is the phone’s ISO range, and in dim light a fast speed shows up as noise rather than a blinking aperture.

Slow speeds on purpose: panning and moving water

Panning

In a pan, you swing the camera to follow a moving subject during the exposure, so the subject stays roughly sharp and the background streaks. The streak length is set by the shutter speed, so lock it in shutter priority and let the camera deal with brightness as the subject passes from sun into shadow.

1. Set 1/60 for cars and motorbikes, 1/30 for cyclists and runners.
2. Use base ISO. Slow speeds in daylight push the aperture toward f/16 or f/22, and a low ISO keeps the camera away from the overexposure limit.
3. Select continuous autofocus (AF-C) and a burst drive mode.
4. Pick up the subject early, match its speed smoothly, shoot as it passes square to you, and keep swinging after the shutter closes.
5. Review. If the background is not streaked enough, go one stop slower. If nothing is sharp, go one stop faster.

The truck was shot at 1/8, three stops slower than the 1/60 starting point above. Speeds that slow give long, dramatic streaks but a low hit rate: expect most frames in a burst to show some blur in the subject too, and keep the few that do not. At ISO 100 that slow speed also pushed the lens to f/16; in brighter light it would have needed f/22 or beyond, and the aperture would have blinked. Stance, focus settings and follow-through are covered in the guide to panning photography.

Moving water

For streams, waves and fountains, put the camera on a tripod, set base ISO and try half a second. Water falling fast needs less time to blur than a slow river. Check the aperture the camera picks: if it is f/16 or f/22, a neutral density filter will bring it back to the sharper middle of the range. The guide to photographing waterfalls covers filters, composition and timing.

This creek shows where the mode ends. A 240 second exposure is far beyond the 30 second limit of shutter priority, so a frame like this is made in bulb mode with the aperture and ISO set by hand. Shutter priority covers the range from a fraction of a second to 30 seconds; past that, the long exposure techniques take over.

Shutter priority vs aperture priority vs manual with Auto ISO

All three modes can produce the same exposure. They differ in which setting stays fixed and which one drifts when the light changes.

• Shutter priority, fixed ISO: You fix: Shutter speed, ISO. Camera adjusts: Aperture. What can go wrong: Runs out of aperture after five or six stops; depth of field changes from frame to frame.
• Shutter priority, Auto ISO: You fix: Shutter speed. Camera adjusts: Aperture, then ISO. What can go wrong: Lens sits wide open in dim light; depth of field is out of your hands.
• Aperture priority with an Auto ISO minimum shutter speed: You fix: Aperture, slowest allowed speed. Camera adjusts: Shutter speed, then ISO. What can go wrong: Speed rises above your minimum in bright light, so blur effects are not repeatable.
• Manual with Auto ISO: You fix: Shutter speed and aperture. Camera adjusts: ISO. What can go wrong: Overexposes if the light is too bright for base ISO; noise rises in dim light.

Against aperture priority. For freezing action, aperture priority with a minimum shutter speed is often the better choice. The camera keeps the ISO at its lowest and gives you speeds faster than your minimum whenever the light allows, and faster never hurts when the aim is to freeze. Shutter priority is the better choice when you want one exact speed and no other: a pan at 1/30, a propeller or wheel that should show some blur, water at half a second. There, a camera that helpfully speeds up in bright light would ruin the effect.

Against manual with Auto ISO. In manual mode with Auto ISO you set the speed for motion and the aperture for depth of field, and the camera floats the ISO. This is shutter priority with the aperture taken back under your control, and many action photographers prefer it for that reason. Its range is also wider: from a base ISO of 100 to a ceiling of 12,800 is seven stops, more than most lenses offer in aperture. Shutter priority still wins in two cases. In bright light at slow speeds, manual with Auto ISO runs out once the ISO reaches its base value, while shutter priority keeps closing the lens for you. And shutter priority leaves one less number to think about while the action is happening. How to shoot in manual mode walks through the manual approach step by step, and camera modes explained covers every other position on the dial.

When shutter priority is the wrong choice

• Depth of field matters. Portraits where you want a soft background, landscapes where you want everything sharp, close-ups: pick the aperture yourself.
• A series must match. Panoramas, time-lapse frames and product sets need identical exposures. Any automatic mode will drift; use manual, or hold a reading with AE lock for a short sequence.
• Studio flash. The camera cannot meter a flash that has not fired yet. Set everything manually.

Want to check you can tell the modes apart and pick the right one for a shot? Try the camera modes quiz.

Common mistakes and misconceptions with shutter priority

Ignoring the blinking aperture. The camera fires anyway and you find dark frames later. Fix: glance at the aperture readout after every change of light, speed or zoom. If it blinks, change the ISO first.

Leaving the ISO at 100 for action. At 1/2000 with an f/5.6 lens, ISO 100 is more than a stop short even in full sun (the correct speed at f/5.6 is about 1/800). Fix: turn on Auto ISO with a ceiling you accept, or set ISO 800 to 1600 on overcast days and 3200 or more indoors.

Thinking S mode makes pictures sharp. A fast speed stops subject movement and camera shake, nothing else. With Auto ISO in dim light the lens goes wide open, depth of field shrinks, and a slightly missed focus looks like blur. Fix: check whether anything in the frame is sharp. If something is, the problem is focus, not the shutter. Camera shake explains how to tell the three causes apart.

Expecting stabilization or a tripod to freeze a moving subject. Image stabilization and a tripod both steady the camera. Neither does anything about a dog running across the frame. Only the shutter speed (or a flash) freezes the subject.

Using a far faster speed than the subject needs. 1/4000 for people walking costs four stops of ISO or aperture compared with 1/250, for no visible gain. Fix: use the slowest speed that reliably freezes the subject, then spend the rest on a lower ISO.

Forgetting that depth of field drifts. The aperture follows the light, so a sequence can swing from f/4 to f/16 as clouds pass. If background blur must stay constant, fix the aperture instead.

Try this: a seven-speed shutter ladder on one moving subject

Find a subject that moves the same way again and again: a road with steady traffic, a fountain, a swing, a dog chasing a ball. It takes about ten minutes.

1. Set shutter priority, ISO 100 (or the lowest your camera offers), and a fixed focal length. Turn safety shift off if your camera has it.
2. Shoot the subject at seven speeds, each one stop apart: 1/2000, 1/1000, 1/500, 1/250, 1/125, 1/60, 1/30. Brace the camera or rest it on something solid.
3. After each frame, write down the aperture the camera chose and whether it blinked. The aperture should change by one stop each time, until the lens runs out at one end or the other.
4. Repeat the three fastest speeds with Auto ISO on, and note the ISO the camera picked.

To judge the result, view the seven frames side by side at full magnification. Find the slowest speed that froze the subject completely, and the speed where blur first looked deliberate rather than accidental. Those two numbers, for that subject at that distance, are yours to keep. Then look at where the aperture first blinked at each end of the ladder: those speeds are the edges of your lens’s exposure budget at ISO 100 in that light.

Frequently asked questions about shutter priority

What does Tv mean on a camera dial?

Tv stands for time value. It is the same mode that other cameras label S: you set the exposure time and the camera sets the aperture. The two labels behave identically.

Is shutter priority or aperture priority easier to learn with?

Aperture priority is the easier everyday mode because the camera almost never runs out of shutter speeds. Shutter priority is the better teacher for motion: it shows quickly what each speed does to a moving subject. Learn both, and use whichever fixes the setting that matters most for the picture in front of you.

Why are my shutter priority photos too dark?

The speed you chose needs more light than the lens can gather at the current ISO, so the camera opened the lens fully and still came up short. Raise the ISO, switch on Auto ISO, zoom out if your lens loses light at the long end, or choose a slower speed.

Does shutter priority set the ISO too?

Only if Auto ISO is on. With a fixed ISO, the aperture is the one thing the camera changes, which is why it runs out of adjustment so much sooner than in aperture priority.

Can I use shutter priority for video?

You can, but the shutter speed for natural-looking motion in video is set by the frame rate, not the subject: about double it, so 1/50 at 24 or 25 frames per second and 1/60 at 30. Shutter priority then changes the aperture during a clip as the light changes, which shows as a shift in brightness and depth of field. Most people filming set exposure manually and control brightness with neutral density filters; camera settings for video explains why.

Seeing stripes or uneven brightness at fast speeds under indoor lights? That is flicker from the lights themselves, and light flicker and banding explains which speeds avoid it.