So, what is the aperture?

It is the hole in the camera lens that determines how much light is able to reach the sensor or film, depending on if you are using a digital or an analog camera.

 

The aperture is usually referred to as an f-number. This is the ratio of focal length to effective aperture diameter. You can set the size of the aperture in the lens with the a called "f-stop". The "f-stop" is the different f-numbers your can set your lens to.

 

Then what happens when you change the aperture to a different f-stop? Let's say  we have a lens that has a range from f/2.8 - f/22. If we set this lens to f/2.8 you are going to get a big opening and a lot of light is going to reach the sensor. On the other hand, if you set the aperture to f/22 the opening is going to be very small and very little light will get through.

 

But this is not the only thing that is going to be affected by changing the aperture. By changing the size you also change your depth of field. The depth of field determents how much of the image that will be in focus. A wide aperture such as f/2.8 will give a shallow depth of field where as f/22 will give a deep depth of field.

 

The shutter is what controls for how long time the sensor collects light. You measure Sutter speed in fractions of a second, for example 1/30 1/60 1/125 1/800. The effect you get from changing the speed is depending on if you choose a long or a short speed. Long shutter speeds can be used to capture movements in a picture. For example if you photograph running water and choose a long shutter time you will see that the water was moving and it will look smooth. But if you choose a short shutter speed you will freeze the movement.

 

The aperture and shutter also affect each other. If you have a small aperture you will need a longer shutter speed and with a large aperture you can use a shorter speed.