What is Aperture?

Aperture can be defined (in photography) as being a �hole or opening through which light is emitted�. But how is this applied in modern photography. Well, put simply, Aperture�s main use in photography is to control the depth of field (DOF) but Aperture is also used in conjunction with your Camer�a shutter speed to control exposure. For those that don�t know, the definition of depth of field is the distance in front and behind an object which remains to be in focus.

Therefore a larger depth of field keeps more of the image in focus and a smaller depth of field focuses on one main part of an image (the focal point) leaving more of the image out of focus.

How is Aperture Measured?

Aperture is measure in f/stops or f/numbers. The lower the f/stop, the greater the aperture (size of the hole that light can pass through) the smaller the depth of field. Therefore more of the image will be out of focus than on a higher Aperture setting.

Therefore, the higher the f/stop, the smaller the aperture and the greater the depth of field. Meaning more of the image will be in focus.

Wow! Now I understand Aperture, how can i use it?

Typically, larger aperatures are used when you want the most of the image in focus, Landscape photography, HDR etc. A smaller aperature are more often used when a photographer only wants a viewer to focus on his chosen subject/focal point, macro photography is a prominent example.

The principles of aperture can also be applied with mor creative photography and can produce some interesting and unique effects.

How do i change the aperture on my camera?

Before we move any further, please understand that aperture of course works with shutter speed, so for know i would suggest that whilst practicing this technique, that you shoot in Aperture Priority Mode, (Av). This allows you to set the aperture, and the camera will choose a suitable shitter speed. This feature is avaiable on pretty much every modern DSLR.

There are too many cameras on the market for me to list how to change the aperture on each. But the appropiate information will be available in your camera�s manual.

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