Camera Mode Dial: PASM and Scene Modes Explained

What the mode dial does

The mode dial is the physical or virtual selector on a camera that sets how much of the exposure process you control versus how much the camera automates. It is the fastest way to change the character of a photo: freeze action, blur a background, or keep everything sharp from near to far.

The letters on the dial P, A (or Av), S (or Tv), and M stand for Program, Aperture Priority, Shutter Priority, and Manual. Together they are called PASM. Most cameras also include a green Auto position and a set of scene modes represented by icons like a mountain, a person, or a flower. Understanding what each of these does is the first step toward making deliberate creative choices rather than accepting whatever the camera guesses.

• P (Program): the camera picks aperture and shutter speed, you keep access to exposure compensation and other adjustments.
• A or Av (Aperture Priority): you set the aperture, the camera chooses the shutter speed.
• S or Tv (Shutter Priority): you set the shutter speed, the camera chooses the aperture.
• M (Manual): you set both aperture and shutter speed yourself.

Program mode (P)

Program mode is sometimes dismissed as a stepping stone to full manual, but that undersells it. The camera sets what it considers a correct aperture and shutter speed pair, but you can shift that pair in sync: for example, ask the camera to use a faster shutter speed and a wider aperture, or the reverse, without leaving Program. You also retain full access to exposure compensation, white balance, ISO, and drive modes.

Program is a practical choice when the light is changing quickly and you do not want to miss a moment while adjusting two settings at once. It is also a comfortable place to start when you are transitioning from full Auto but are not yet ready to commit to Aperture or Shutter Priority. If you are choosing a first interchangeable lens camera, most of the models in our best mirrorless cameras guide have a mode dial that includes Program.

Aperture Priority (A or Av)

Aperture Priority lets you choose the f-number while the camera sets the shutter speed to match. This is the mode most photographers use for portraits, where a wide aperture like f/1.8 isolates the subject with a soft background, and for landscapes, where a narrow aperture like f/11 keeps the whole scene sharp.

Because depth of field is one of the strongest visual tools in photography, Aperture Priority is often the first creative mode people adopt. The camera handles the risk of an unusable shutter speed, though you still watch the shutter speed readout and raise the ISO when it drops too low. For a fuller explanation of how the aperture interacts with shutter speed and ISO, see our exposure triangle guide.

If your main interest is controlling how much of the image is in focus, Aperture Priority is the mode to learn first. The same exposure logic applies across sensor sizes, but the physical results differ: a Micro Four Thirds camera at f/2.8 gives a deeper depth of field than a full-frame camera at the same f-number, as explained in our sensor size guide.

For camera shopping, whether you want a compact model with a fast lens or a full-frame body with shallow depth of field, Aperture Priority will be the mode you use most. Compare the best compact cameras and the best full-frame mirrorless cameras to find a body that places the dial where you can reach it comfortably.

Shutter Priority (S or Tv)

Shutter Priority does the reverse: you set the shutter speed and the camera chooses the aperture. This is the mode for freezing motion, like a bird in flight or a child running, and for intentional blur, like a waterfall or light trails from traffic.

A fast shutter speed, such as 1/1000 second, stops action; a slow one, such as 1 second, lets moving subjects blur. The camera then picks whatever aperture gives a correct exposure with the ISO you have set. The trade-off is that you give up direct control over depth of field, so it is best used when motion, not background blur, is what the photo depends on.

Shutter Priority is especially useful with telephoto lenses, where small movements become visible in the frame. The reciprocal rule suggests choosing a shutter speed at least as fast as the inverse of the focal length, but image stabilization changes that math. Cameras with in-body stabilization, like many of the picks in our best APS-C cameras guide, let you shoot several stops slower than you could otherwise.

For more on how shutter speed affects motion and sharpness, including readout artifacts and mechanical versus electronic options, see the shutter speed guide and the shutter types guide.

Manual mode (M)

Manual mode hands you full control over both aperture and shutter speed, and usually ISO as well. It is the mode to use when the camera's meter is likely to be fooled: high-contrast scenes, heavily backlit subjects, or a deliberately dark and moody exposure that you want to hold across a series of shots.

Manual is not a badge of expertise; it is a tool for consistency. Event photographers who shoot a staged interview, product photographers working with flash, and landscape photographers on a tripod all use Manual to keep exposure locked from frame to frame. The camera's built-in meter still helps as a reference, and exposure compensation behaves differently in Manual, so it is worth reading the exposure compensation guide before switching between modes.

If you are new to Manual, start in a situation where you have time to think: a still subject, a tripod, and no deadline. Review the histogram or the camera's live preview after each shot and adjust one setting at a time. For guidance on reading the histogram, see the histogram and zebra guide.

Scene modes: what they are for

Scene modes are automated presets that bundle several decisions at once. A portrait mode typically favors a wider aperture for background blur, a landscape mode stops down the aperture and may sharpen greens and blues, and a sports mode biases toward a fast shutter speed and continuous autofocus.

The icons help in a pinch: a mountain for landscapes, a face for portraits, a flower for close-ups, a running person for sports, and a moon or star for night scenes. The exact set and behavior differ across brands, but the principle is the same. These modes are useful when you are passing the camera to someone else, when you are shooting a subject you have never tried before, or when you simply want a good starting point and plan to tweak from there.

Scene modes also handle problems that a simple Auto mode might miss. Night portrait mode uses flash with a slow shutter to light the person and let the background register, and sports mode raises the shutter speed to freeze movement. On a bridge camera or a beginner DSLR, scene modes are often the practical way to get a specific look without learning PASM first.

If you are choosing between cameras, look at how easily you can reach the scene modes on the dial. Some bodies put them in a dedicated position; others require a trip through a menu. A camera with a physical dial for scene modes, like several of the best bridge cameras, is friendlier when you want to switch from landscape to sports quickly.

Full Auto and the green position

The green Auto position, sometimes labeled A or with a green camera icon, is a full automatic mode where the camera decides aperture, shutter speed, ISO, white balance, and often focus logic, and hides most menu options that could confuse a first-time user. It is a reliable baseline for snapshots and for handing the camera to someone who has never touched it before.

Auto is not a failure. But if the camera keeps choosing settings you do not want, shoot in Program instead: Program gives you the same automatic exposure baseline with the freedom to adjust white balance, drive mode, or exposure compensation. That single change moves you from being a passenger to having a steering wheel.

For a camera where Auto produces consistently good results, many compact models in the best 1-inch cameras guide have responsive auto modes paired with PASM for when you want control.

How to choose the right mode for your use

There is no single best mode, only the right mode for the moment. The matrix below matches common shooting situations with the mode that gives you the fastest path to the result you want.

What to pick for your use

Questions

What is the difference between A and Av on the mode dial?

They are the same mode with different names. A (aperture value) is used by some brands like Sony, Canon, and Nikon; Av (aperture value) is the Canon variant. Both mean Aperture Priority: you choose the f-number and the camera sets the shutter speed.

Is it bad to shoot in Auto mode?

Not at all. Auto is useful in unpredictable situations or when you hand the camera to someone else. If Auto frequently gives you a different image than you had in mind, switch to Program first, which keeps the automatic exposure but gives you back control over white balance, exposure compensation, and drive modes.

When should I use Manual mode instead of Aperture or Shutter Priority?

Use Manual when you need the exact same exposure across many shots and the meter is likely to move around, such as in a studio with flash or a backlit scene. Use Aperture or Shutter Priority when the lighting is consistent enough and you only need to control one variable.

What is the best mode for sports photography?

Shutter Priority is the most direct choice because it lets you lock in a fast shutter speed. Pair it with continuous autofocus and, on many cameras, a burst drive mode to keep up with fast action.

What do scene mode icons like the mountain or flower mean?

The mountain icon is landscape mode, which typically uses a narrow aperture and vivid color for faraway scenes. The flower icon is macro or close-up mode, which biases focus for nearby subjects. The running person icon is sports mode, which selects a fast shutter speed. These all stack that subject's typical needs into one turn of the dial.

Does the mode dial work the same on a compact camera as on a mirrorless or DSLR?

Yes, the letters mean the same things across camera types. What changes is how many scene modes are available and how quickly you can reach them. Some compacts hide PASM in a menu, while most mirrorless and DSLR bodies expose them directly on the dial.