Camera modes decide who sets the exposure: you, the camera, or the two of you splitting the job. The dial marked Auto, P, A (or Av), S (or Tv) and M does not change how good your pictures can be. It changes which settings you choose yourself and which ones the camera fills in, and that decides how fast you can work and whether the picture comes out the way you meant.
The short version: in Auto and Program the camera picks both the aperture and the shutter speed. In aperture priority you pick the aperture and the camera picks the shutter speed. In shutter priority it is the other way round. In Manual you pick both.
The one job every exposure mode shares
Every mode except Manual works the same way underneath. The camera’s light meter reads the scene and decides how much light the picture needs, its idea of a correct exposure. That total is fixed by the meter, not by the mode. The mode only decides which control the camera is allowed to move to reach that total.
That is what “priority” means. In aperture priority your aperture has priority: the camera will not touch it, so it moves the shutter speed instead. In shutter priority the shutter speed is protected and the aperture moves. Two things follow, and they clear up most of the confusion about modes:
- Turning your dial in a priority mode does not change brightness. Open the aperture one stop in aperture priority and the camera halves the shutter time. The photo is just as bright. What changes is how it looks: depth of field in one case, motion in the other.
- A mode cannot make a better exposure than the meter. If the meter is fooled by snow or a black background, every automatic mode is fooled in the same way. The fix, exposure compensation, works the same in all of them.
Who sets what, mode by mode
ISO is the third setting, and Auto ISO changes the picture. With Auto ISO on, the camera gets a second control to move, so aperture priority leaves the camera two settings (shutter speed and ISO) instead of one.
| Mode | Aperture | Shutter speed | ISO | Exposure compensation |
|---|---|---|---|---|
| Auto | Camera | Camera | Camera | Usually locked out |
| Scene modes | Camera, with a bias | Camera, with a bias | Camera | Often locked out |
| Program (P) | Camera (you can shift the pair) | Camera (you can shift the pair) | You, or Auto ISO | Yes |
| Aperture priority (A, Av) | You | Camera | You, or Auto ISO | Yes |
| Shutter priority (S, Tv) | Camera | You | You, or Auto ISO | Yes |
| Manual (M), fixed ISO | You | You | You | Changes no setting; on some cameras it shifts the meter’s zero mark |
| Manual (M) with Auto ISO | You | You | Camera | Yes, on most cameras |
| Bulb (B) | You | You, by holding the button | You | No |
One scene, the same exposure in every mode
Here is the idea that makes modes easy: any mode can produce exactly the same photo. A mode is a way of working, not a quality setting. Take a street on a bright overcast day where, at ISO 100, the meter wants the equivalent of f/8 at 1/125. Each mode can land there:
- Program: What you do: Nothing, or turn the dial to shift. What the camera answers: Picks a pair such as f/5.6 at 1/250; shifting one stop gives f/8 at 1/125. Result: f/8, 1/125.
- Aperture priority: What you do: Set f/8. What the camera answers: 1/125. Result: f/8, 1/125.
- Shutter priority: What you do: Set 1/125. What the camera answers: f/8. Result: f/8, 1/125.
- Manual: What you do: Set f/8 and 1/125, check the meter reads zero. What the camera answers: Nothing; it only shows the meter. Result: f/8, 1/125.
The four pictures are identical. The difference shows when something changes. If the cloud thins and the light doubles, aperture priority answers with 1/250 and keeps your f/8, shutter priority answers with f/11 and keeps your 1/125, and Manual does nothing, so the picture comes out a stop too bright until you notice. Choosing a mode is choosing which of those three behaviors you want when the light moves. The same exposure can be reached with many pairs, f/4 at 1/500, f/5.6 at 1/250, f/11 at 1/60, f/16 at 1/30; the exposure triangle page has a tool that walks through them.
The simulator below lets you see this happen. Set f/2.8 in Av and note the shutter speed the camera picks. Switch to Tv and dial in that same shutter speed: the camera comes back to f/2.8, and the picture is the same.
Want other scenes to try this on? The full camera simulator has eight, and 21 challenges.
Auto and scene modes: the camera decides
In Auto the camera sets aperture, shutter speed, ISO, white balance, usually the focus mode, and often whether the flash pops up. You frame and press. It is a sound choice when you hand the camera to someone else or have no time at all, and it gets ordinary scenes right most of the time.
Its limit is that it cannot know you wanted the waterfall blurred, the background soft, or the museum left without flash. Its choices are safe middles.
Scene modes (Portrait, Landscape, Sports, Night, Macro and so on) are Auto with a lean. Portrait leans toward a wide aperture for a soft background. Landscape leans toward a smaller aperture and stronger color. Sports leans toward a fast shutter speed and continuous focus. Night may use a slow shutter speed, sometimes with flash. On many cameras these modes also save JPEG only and lock out exposure compensation and ISO, which is the main reason to move on from them. Anything a scene mode does, aperture or shutter priority does more precisely, because you set the number instead of a hint.
Program mode (P): the camera picks, you can steer
Program sets the aperture and shutter speed pair for you, like Auto, but gives back everything else: ISO, white balance, focus, flash, file format and exposure compensation. That makes it a fast, capable mode, not a learner’s mode. When a street scene or a party changes faster than you can think about settings, P with compensation lets you put your attention on timing.
Most cameras also let you shift the program. Turn the main dial and the camera steps through equivalent pairs at the same brightness: if it chose f/5.6 at 1/250, one way gives f/4 at 1/500, the other gives f/8 at 1/125. Some cameras show a mark such as P* while a shift is active. On many the shift is cancelled when you change mode, when the meter times out or when the camera switches off, but not on all, so check before you trust it. For how the camera picks its pair in the first place, see auto exposure.
One habit of Program and Auto worth knowing: when the flash fires indoors, they usually hold the shutter at a hand-holdable speed, around 1/60. Aperture priority often does not, which is a classic surprise covered below.
Aperture priority (A or Av): you choose how much is sharp
You set the f-number; the camera sets the shutter speed. Since aperture decides how deep the zone of sharpness is, this is the mode for any picture where that matters most: a portrait at f/2 with a soft background, a landscape at f/11 sharp from the rocks to the peaks, a street scene at f/8 where you want room for error in focus.
The catch is that the camera will pick any shutter speed it needs, however slow. Set f/16 in a lamp-lit room at ISO 400 and it can easily answer with half a second or longer, which blurs from camera shake and from anything that moves. Glance at the shutter speed in the viewfinder before you press. Two fixes: open the aperture or raise the ISO, or turn on Auto ISO with a minimum shutter speed. Then the camera keeps the ISO low until the shutter would fall below your limit, and raises ISO instead of going slower.
A worked example. In the street scene from earlier (f/8 at 1/125 at ISO 100), set f/8 with Auto ISO and a minimum shutter speed of 1/250. The plain answer, 1/125, is below your limit, so the camera holds 1/250 and raises ISO one stop to 200. Same brightness, faster shutter, a little more noise.
The flash surprise: in aperture priority indoors, many cameras expose the room by the existing light and let the flash light only the subject. That can mean a shutter speed of 1/15 or slower, with the subject frozen by the flash and ghosting around it. It is useful once you know it, and flash and ambient light explains how to control the balance.
Want more on exposure compensation and Auto ISO in this mode? Aperture priority mode covers both, and when to switch to Manual.
Shutter priority (S or Tv): you choose how motion looks
You set the shutter speed; the camera sets the aperture. This is the mode for pictures where movement is the point. A fast speed such as 1/1000 freezes motion in a running child or a bird taking off. A slow one such as 1/15 or 1/8 turns movement into motion blur, and if you swing the camera with a passing car at those speeds, panning, the car stays fairly sharp while the background streaks. It is also the mode for keeping a safe speed in changing light: set 1/250 for people moving at an event and the camera adjusts the aperture as you walk from window light to shade.
The catch is that the aperture has a fixed range, and the camera can run out of it. Most cameras warn you by blinking the aperture number or showing it in red. The warning means the exposure will be wrong by however far the scene is beyond the lens, and the camera will take the picture anyway. The numbers make it clear:
- Too dark: in a dim room where f/2.8 at ISO 100 gives 1/15, choosing 1/1000 asks for six more stops of light (1/15 to 1/30, 1/60, 1/125, 1/250, 1/500, 1/1000). The lens cannot open past f/2.8, so the photo is six stops dark unless you raise ISO six stops, from 100 to 6400, or accept a slower speed.
- Too bright: in full sun at ISO 100, f/22 gives about 1/60. Choosing 1/15 is two stops more light than f/22 can cut, so the photo is about two stops too bright. A 3 stop ND filter fixes it: behind the filter the camera can answer 1/15 with about f/16.
Try it in the simulator: switch to Shutter priority, pick 1/1000 or faster for the moving subject and let the camera choose the aperture. It cannot get a good exposure on its own here, so finish the job yourself.
Seeing the aperture blink in the viewfinder? Shutter priority mode covers the warning and how to clear it, plus shutter speeds for common subjects.
Manual mode (M): you choose both, and nothing drifts
In Manual mode you set aperture, shutter speed and ISO yourself. The meter still works: a scale in the viewfinder, usually marked from -3 to +3, shows how far your settings are from what it suggests. But it only advises. Nothing you set changes unless you change it.
That is Manual’s real strength, and it is not the one usually given. People say Manual is for scenes that fool the meter, but exposure compensation fixes a fooled meter in A, S and P just as well. What Manual alone gives you is consistency: the exposure stays the same while the framing changes. That matters when:
- The light is fixed but the background is not. A performer in a spotlight on a dark stage: as you reframe, an automatic mode keeps re-reading all that black and brightens the face too much, then less, then more. In Manual you set the exposure for the face once, and every frame matches. Concert photography lives on this.
- Frames must match. A panorama shot in an automatic mode gets a different exposure for each frame as the camera points at brighter and darker parts of the scene, and the joins show as bands. Manual keeps every frame identical.
- You light the scene yourself. With studio flash the meter cannot see the flash before it fires, so it has nothing useful to say. You set the camera and adjust the lights.
- There is too little light to meter. A dark night sky gives the meter almost nothing to read, so for astrophotography and much night photography you set a known starting exposure and adjust from test shots.
Manual is also the best mode for learning how the settings relate, because every change is yours. For a step-by-step method, see how to shoot in manual mode.
Manual with Auto ISO
Turn on Auto ISO in Manual and you get a hybrid: you fix the aperture for depth of field and the shutter speed for motion, and the camera moves ISO to keep the exposure right. It suits events, sport, street and wildlife, where the light changes all the time but you never want to give up the two settings that change how the picture looks. On most cameras exposure compensation works again in this setup, because the camera now has a setting to move; in Manual with a fixed ISO it has nothing to move. It is the wrong choice for the consistency cases above: Auto ISO would change the exposure as the framing changes, and with studio flash it fights the lights.
Bulb and Time: exposures longer than the dial
Most cameras offer timed shutter speeds up to 30 seconds. For longer, Bulb (B) keeps the shutter open for as long as you hold the button down, or for as long as a remote release is locked. Some cameras also have Time (T), where one press opens the shutter and a second press closes it. Both are Manual in every other way: you set the aperture and ISO. Use a remote release or the camera’s app so your finger does not shake the camera. Bulb is for star trails, fireworks and very dark long exposures; bulb mode has the method and the timing arithmetic.
Custom modes (C1, C2, C3)
Many cameras have custom positions on the dial, often C1, C2 and C3, or a menu that saves a full setup. Each stores a mode with everything else: aperture, Auto ISO limits, focus and drive mode. You might keep one for portraits (aperture priority, f/2.8, Auto ISO with a 1/200 minimum) and one for moving subjects (shutter priority, 1/1000, Auto ISO, continuous focus). One turn of the dial replaces a dozen menu changes.
Want starting settings for a particular kind of shot? The camera settings cheat sheet has them for each genre in one table.
When the meter is wrong, every mode is wrong
A meter assumes the scene averages out to middle gray. Ordinary scenes do, and the automatic modes nail them. Scenes that are mostly bright or mostly dark do not. A field of snow like the one at the top of this page comes out gray and too dark. A black dog on a dark sofa comes out gray and too bright. Changing modes does not help, because every automatic mode trusts the same reading.
The fix is the same in A, S and P: dial in exposure compensation, about +1 to +2 for snow and -1 for mostly dark scenes, and the camera moves its chosen control to match. In Manual you simply set the exposure that much above or below the meter’s zero. How the meter reads the frame also depends on the metering mode, and you can hold a reading while you reframe with exposure lock.
Judge the result on the histogram, not by how bright the screen looks, since the screen looks dark in sunlight and bright in a dim room. A graph crammed against the left edge means lost shadow detail; against the right edge means blown highlights.
Does the meter keep misjudging your scenes? Exposure compensation explains why it gets fooled and gives starting values by scene.
Cameras with no mode dial, and phones
Some cameras have no P, A, S, M dial at all. Instead the lens has an aperture ring and the top plate has a shutter speed dial, and each has an A (automatic) position. Set the aperture ring to a number and the shutter dial to A, and you are in aperture priority. Reverse them for shutter priority. Both on A is Program; both on numbers is Manual. The modes are the same four, just set with two controls instead of one.
A phone’s main camera app works like Program or Auto all the time: it picks shutter speed and ISO, and you steer it with the exposure slider, which is exposure compensation by another name. Most phone lenses have a fixed aperture, so there is no aperture priority. A “Pro” or manual mode, where offered, lets you set shutter speed and ISO yourself, which is shutter priority or Manual. Phone camera settings covers what each control does.
Exposure modes for video
Video is usually shot in Manual, because an automatic mode changes brightness during a clip as the scene changes, and viewers notice. A common starting point is a shutter speed of about double the frame rate, 1/50 at 24 or 25 frames per second and 1/60 at 30, which gives motion a natural amount of blur. With the shutter fixed, you control exposure with aperture, ISO and, in daylight, an ND filter. Aperture priority can help when you walk between very different light, such as from indoors to outdoors, because the camera adjusts as you go. Camera settings for video goes further.
Which mode for which situation
- Portrait with a soft background: Mode: Aperture priority. Why: The aperture sets how soft; the shutter speed rarely matters.
- Landscape on a tripod: Mode: Aperture priority or Manual. Why: f/8 to f/11 for depth; a slow shutter is fine on a tripod.
- Sport, wildlife, children: Mode: Shutter priority, or Manual with Auto ISO. Why: A fast shutter speed is the setting that must not change.
- Panning, blurred water: Mode: Shutter priority. Why: The amount of blur is the picture.
- Street, travel, changing light: Mode: Program or aperture priority, with Auto ISO. Why: Fast to use; you keep compensation for tricky light.
- Stage, spotlit subject: Mode: Manual. Why: The light on the subject is constant; the dark around it fools the meter.
- Panorama: Mode: Manual. Why: Every frame must have the same exposure.
- Studio flash: Mode: Manual. Why: The meter cannot see the flash.
- Night sky: Mode: Manual, or Bulb past 30 seconds. Why: Too little light to meter; you want a fixed, repeatable exposure.
- Handing the camera to someone: Mode: Auto. Why: No decisions needed.
Common mistakes and misconceptions about camera modes
- “Manual gives better pictures.” It gives the same pictures with more work, except where consistency matters. Pick the mode that gets you the right settings fastest.
- “Auto and Program are the same.” Both pick the aperture and shutter pair, but Program gives you back ISO, flash, white balance, file format, compensation and program shift.
- Thinking the aperture changes brightness in aperture priority. It changes the shutter speed. If pictures are too dark or too bright, the fix is compensation.
- Not watching the shutter speed in aperture priority, or ignoring the blinking aperture in shutter priority. Both mean the camera’s answer is not one you can use.
- Forgetting Manual does not follow the light. Settings right in shade will be badly overexposed when you step into sun. Check the meter after every move, or switch on Auto ISO.
- Turning the compensation dial in Manual with a fixed ISO and wondering why the picture does not change. With no automatic setting to move, it changes nothing, or at most shifts the meter’s zero mark. It changes the exposure in Manual only with Auto ISO on.
- Leaving compensation or a program shift from the last scene. Set compensation back to zero when you move on.
Try this: one scene in four modes
Ten minutes, any camera with P, A, S and M. Pick something in steady light that has a little movement, such as a fountain, a fan or traffic at a crossing. Use the same ISO throughout.
- In aperture priority, set f/8 and take a picture. Write down the shutter speed the camera chose.
- In shutter priority, set that shutter speed. Check the camera answers with f/8 (or within a third of a stop).
- In Manual, set both by hand and check the meter reads zero. Take the picture.
- In Program, shift until you reach the same pair, and take the picture.
- Now break it on purpose: in shutter priority set 1/1000, then 1/8. Watch what the camera does to the aperture, and whether it warns you.
How to judge it: the first four frames should look the same on the histogram and on screen. If they do, you have seen that the mode is a way of working, not a look. In the last two, the movement should freeze in one and blur in the other, and you should be able to say which control the camera moved and why.
Want to check you can tell the modes apart? Try the camera modes quiz.
Questions people ask about camera modes
What do Av, Tv, A and S stand for?
Av means aperture value and Tv means time value, the labels some cameras use for aperture priority and shutter priority. Other cameras label the same modes A and S. They work the same way whatever the letters.
Which camera mode should I learn in?
Aperture priority is the easiest start: you make one decision and see its effect on depth of field straight away. Move to shutter priority on moving subjects, then try Manual where the light is steady, such as a lamp-lit room, so each change you make is the only thing changing.
Do professional photographers always shoot in Manual?
No. Many use aperture priority or Manual with Auto ISO most of the time, and full Manual for studio flash, stages, panoramas and night skies. The right mode is the one that gives the control the situation needs with the least effort.
Why is my photo too dark even in a priority mode?
Either the meter was fooled by a bright scene, which needs plus compensation, or the camera ran out of range, shown by a blinking aperture or shutter value. Check both before changing modes, because a different automatic mode will usually make the same mistake.
Does the mode affect RAW files?
No. The mode only decides how the aperture, shutter speed and ISO were chosen, and the RAW file records the result the same way. The exception is Auto and some scene modes, which on many cameras save JPEG only; see RAW vs JPEG for why that matters.