Mastering Exposure: Exposure Modes

Exposure modes
Don’t panic – you don’t need to learn all those apertures and shutter speeds off by heart (though doing so would be useful). Modern DSLRs can control both of these elements for you automatically. The trouble is, although you’ll get a fair record of what you saw, if you leave everything to the camera then you’re not in creative control of your pictures, your camera is. While the Program and Auto modes are useful for quick snaps, the sooner you can graduate to the more creative modes, the sooner you’ll be able to impose your own vision on your pictures. Your camera will then become an artist’s tool rather than simply a recording instrument. Here is a look at the modes found on a typical digital SLR.

Auto mode
In this ‘mother knows best’ mode, the camera makes all the decisions about what exposure to set. You can’t override it in any way, and your only input is to press the shutter at the right time.

Program Mode
Superficially the same as Auto, except that if you don’t agree with the settings the camera has chosen there is some scope to override them.  You can, for example, choose to add flash or change the particular shutter speed/aperture combination to obtain more depth of field than the camera had set. This makes it an ideal mode for the slightly more knowledgeable user.

Aperture Priority
This mode asks you to choose which aperture you want and the camera then matches it with the shutter speed that will provide, in its opinion, a correct exposure. This is probably the most popular mode with experienced photographers since by taking control over the aperture it enables them to determine the most fundamental aspect of the composition – how much of it is rendered in focus.

Shutter Priority
In this mode you get to choose which shutter speed you want to use and the camera then selects the aperture required for the correct exposure. This is ideal for action photography where you want to control how sharp or blurred your moving subject will be recorded. It can also be useful in lower light conditions where you don’t want to go below a hand-holdable shutter speed.

Manual
The camera tells you what exposure it thinks you should give, and it’s up to you how you use that information. Unlike the Priority modes, where the exposure adjusts for changing light conditions, in Manual it won’t, so you’ll need to be aware of light levels. Manual is ideal for situations where exposure needs to be constant, such as shooting panoramas that you’ll want to stitch together later.

Scene/subject modes
Most digital cameras offer a selection of scene modes. By telling the camera what you’re photographing, it can choose the parameters to match. Shooting a portrait? Then a wide aperture will be useful. Scene modes can also adjust the white balance, sharpness levels etc, to suit the subject too. They’re a good stepping stone from Auto, but you’ll get more fine control from the Priority modes.