Lessons 2 · Using your camera
Auto, P, A, S and M
The mode dial decides who chooses the aperture and the shutter speed: you, the camera, or both of you. In every mode the meter does the same job, measuring the light. The modes only differ in which settings you are allowed to move.
| Mode | You choose | The camera chooses | Use it for |
|---|---|---|---|
| Auto | Nothing | Aperture, shutter, ISO, often more | Handing the camera to someone else |
| P Program | Exposure compensation, ISO | Aperture and shutter | Snapshots when you just want a good exposure |
| A Aperture priority | Aperture | Shutter speed | Portraits, landscapes, most everyday photos |
| S Shutter priority | Shutter speed | Aperture | Sport, kids, pets, moving water |
| M Manual | Aperture and shutter | Nothing, unless Auto ISO is on | Night, long exposures, studio, tricky light |
Try this: Switch between Auto, P, A, S and M. In each mode, notice which sliders you can move and which ones the camera moves for you (marked AUTO).
Auto and P
Auto is designed to never get it badly wrong, and that is its weakness: it does not know whether you want a blurry background or a frozen ball. P (program) picks the same kind of settings, but lets you shift the brightness with exposure compensation and choose the ISO. On most cameras you can also turn a dial in P to swap between "wide aperture, fast shutter" and "small aperture, slow shutter" pairs that give the same exposure. This is called program shift.
A and S: the two you will use most
The priority modes let you control the side effect you care about and leave the brightness to the camera:
- In A, set f/1.8 for a soft background or f/8 for a sharp landscape. The camera finds the shutter speed. Watch that it does not drop below the speed you need to avoid blur.
- In S, set 1/1000 s to freeze a runner. The camera opens the aperture to compensate. If it runs out of aperture, the picture gets darker, and the aperture value blinks in the viewfinder.
M: manual, and manual with Auto ISO
In manual you set aperture and shutter, and the meter scale shows whether the result will be brighter or darker than the camera expects. Manual is the best choice when the light is constant but the meter would be fooled: a stage, a night street, a series of photos that must all match.
Modern cameras offer a powerful hybrid: M with Auto ISO. You fix the aperture (for depth of field) and the shutter (for motion), and the camera picks the ISO. It is the favourite mode of many sport and event photographers, because they control both side effects and the brightness still adapts.