Digital cameras offer a range of different shooting modes, usually on a main mode dial on the top of the camera. These may be referred to as exposure modes, since they are mainly to do with the camera’s exposure settings.
Just about all cameras offer a point and shoot Auto mode, often marked in green on the camera’s mode dial. In this mode, the camera takes care of everything, including the shutter speed, lens aperture, autofocus and even the on-camera flash.
Flash is not always ideal, of course. It’s useless in a giant floodlit sports stadium or concert, or in a theatre or museum, and is likely to get you ejected. Some cameras have a No Flash mode which is really useful in these conditions, since it’s just as automatic as the full Auto mode, but the flash is disabled.
Many cameras also offer Scene modes, especially cheaper point and shoot models. These scene modes consist of camera settings chosen for very specific kinds of subjects, such as sports, landscape, macro, portrait and so on. They don’t just change the camera’s exposure and focus settings, they may also adjust the in-camera image processing to give more saturated colors in food shots or softer details in portraits.
Scene modes are just variants on the camera’s basic Auto mode. They might be useful for novices unsure about the best camera settings, but you don’t have any real control over what the camera is doing or why, so more experienced camera users will usually avoid them.
The preferred option for most photographers is to use the so-called ‘PASM’ modes that you get on more advanced cameras. This stands for Program AE, Aperture priority, Shutter priority and Manual modes – a standard set of four options for controlling exposure with the lens aperture and shutter speed. Other settings normally handled by a camera’s Auto or scene modes, such as the autofocus settings or color rendition, are set separately via the camera menus.
In Program AE mode, the camera chooses both the shutter speed and the lens aperture automatically, choosing a combination that gives a good compromise between avoiding camera shake and getting reasonable depth of field. You can vary this combination using the camera’s ‘Program Shift’ mode (Nikon calls it ‘Flexible Program’ if you want faster shutter speeds or smaller lens apertures, for example – the camera will always adjust the other setting to keep the exposure ‘in balance’.
Aperture priority mode is for when you want to choose the lens aperture but you’re happy for the camera to automatically select the shutter speed to give the correct exposure. It’s useful if you want to deliberately use a wide lens aperture to give background blur in a portrait shot, for example, or a small aperture for maximum depth of field in a landscape.
Shutter priority mode is useful when you want to prevent or create movement blur in a picture – the camera will then automatically select the lens aperture to give you the correct exposure. You might use shutter priority mode to make sure your shutter speed is fast enough to avoid camera shake, for example, to freeze a fast-moving subject like a soccer player, or to give just the right amount of movement blur in a panning shot of a horse or a race car.
Manual (M) mode puts you in complete control of both the lens aperture and the shutter speed. The camera will still recommend the best exposure but you can use it or ignore it. Manual mode is useful when you already know the exposure you need, either through experience or when you’re using a handheld light meter. It’s also very useful when you want to keep a consistent exposure across a series of pictures taken in the same conditions without the camera changing the exposure on its own.