Depth of field

The ‘Depth of Field’ refers to how much of the image is in focus. When only a small slice on either side of the focal plane is in focus an image is said to have a ‘shallow depth of field’.

The depth of field is controlled by the aperture, so DSLR’s need to be on Manual or ‘A’perture priority. Compacts may have a ‘portrait with blurry background’ setting or similar, and some compacts may be able to use the macro (tulip/flower) setting to some extent.

Aperture is the opening in the lens of your camera that controls how much light falls onto the sensor.

 ·      A large/wide aperture will create a small depth of field.

•   A wide aperture will let in more light.This can be useful if it is not a bright day because it will mean you can use a shorter shutter speed, preventing camera shake.

•   When using a small depth of field it is important to focus carefully, because if your aperture is too big parts of the subject you are photographing may be out of focus as well as the background/foreground. If focusing on the eyes in a portrait it might not matter, but if only the tip of the nose is in focus your image will look odd.

·      Be aware that your aperture is dictated by your lens, and that different lenses create different effects. Experiment with your own equipment. Also Zoom lenses may not maintain the same aperture throughout, look for the numbers on your lens or camera body.