Getting started in photography can be mind boggling with all the different terms. Over the next few posts I will show and describe some of the terms used. First up is “Aperture.” In simple terms this controls the amount of light getting into the camera and the area of focus.
Simple? It is a little more complex though. The amount of light allowed through is controlled by essentially a hole of which the photographer can change the size of. The size of the hole is represented by an “f” number. For example f1.2, which is a large aperture, means the hole is big, f22, which is a small aperture, means the hole is small.
Which value you use depends on a number of things. Let’s start with what the difference is. With a small aperture such as f22, because the hole is smaller it allows more of the image to be in focus and sharp. This is called the “Depth of Field.” The down side if that you will require a longer exposure time, but is ideal for landscape photography.
A large aperture such as f2.4 has a larger hole and so more light can get in giving shorter exposure times. However because of the bigger hole, less of the image will be in focus. This is ideal for portraits where you want a person, or just their head, in focus and the rest, the background, to be out of focus.
There is no golden rule of when to use a specific aperture, a simple guideline I go by is do I want the background in or out of focus? In focus go for a smaller aperture, f11 and up, otherwise go for a large aperture, f5.6 or smaller.
Next time I will post some examples, real ones.