Basics about Photography Part 1: Aperture

There are 3 fundamental things in photography that everyone should know about: Aperture, Shutter Speed and ISO. In the next few posts I'll try to describe them as simple as possible. In this one I'll talk about aperture, but check back soon for the other two.

Aperture
The aperture tells you how wide lenses will open and there are 2 functions of it.

The first one is to isolate the subject by making the background blurry.

• Smaller f-number: Isolated subject
• Larger f-number: Focus on all

Here are some examples:

Large f-number - focus on all	Small f-number - blurry background

Think about it exactly as a human eyes work.

Just as an experiment, take a pen in front of you (or any other subject) and then close your eyes a little bit. You will still see the pen in full focus, but everything around it will appear unclear. To achieve that effect with your camera the f-number should be small (for example f/1.4).

On the other hand, when you open your eyes widely you will see clearly both, the pen and everything around it. That effect could be achieved by having the f-number big (for example f/22).

The second function of aperture has an effect on amount of light coming through the camera.

• Smaller f-number: More light
• Larger f-number: Less light

Sounds confusing because it's opposite, so I'm going to illustrate that with a simple drawing that I made by my self (be gentle):