Aperture

What is it?

Aperture is a way of controlling how much light comes into your camera. It’s based on the size of the hole in your lens. By changing lenses you can improve the maximum aperture.

How do I use it on my camera?

Depending on the camera make and model you have, by using the A or Av (Aperture Priority) mode on your camera dial or menu, you can select the F number that you want the photo to be taken at, the camera will set the shutter speed to maintain the correct exposure. You would use the main scroll or menu to change the F number.

What does it do to my pictures?

Simply, the smaller the F number you use the less will be in focus in  your pictures. This will make the object in focus stand out more.  However, there are times that you want lots of the picture in focus, like a landscape or a group of people. To get all of the picture in focus use a larger number.

Small F number: the flower is only thing in focus

Large F number: the flower in the foreground and the flowers in the background are not separated. The flowers in the background are distracting.

Examples

F number 11: gives a lot of depth in this picture

Small F number: the water closest is in focus.

Small F number: the back ground is separated from the subject

Larger F number: more in focus, the foreground and background are both parts of the picture

Using a larger F number: the subject and his surroundings are both part of the picture

F number 22: all of the above image is in focus

Try This

Get your camera, set it to Aperture Priority mode, start at the smallest number you can and then take a series of pictures of the same thing changing the  F number. Note how your pictures are changing. What else is changing when taking these pictures?

Have a read about Shutter Speed and ISO.