Aperture Explained

How Aperture Works

aperture works by adjusting the size of a lenses aperture ring and the amount of light that enters your camera, if the aperture is wide open lots of light gets in, likewise if the aperture is small less light will get in.

How is Aperture Measured

Aperture is measured in “f stops” and as you can see in the chart below. At f/1.4 the aperture is wide open and as the numbers advance to f/8 the aperture gets smaller. Its confusing but remember the larger the F stop the smaller the aperture.

Whats the point?

Lets say its a bright sunny day and your taking a photo of a single flower, you take the shot and notice that the flower is in sharp focus but so is the background. Having the background in focus looks noisy and detracts from your main subject (the flower). Ideally what you want is for the flower to be in focus and for the background to be out of focus or blurry, thus making the flower stand out.
This is achieved buy adjusting your cameras aperture. If your in auto mode or “P” Priority mode the camera will automatically chose your aperture for you and if it a bright day the camera will chouse a large aperture such as f/16. A large aperture will give you a wide depth of field (both the background and foreground will be in focus) we need to tell the camera that we want a smaller aperture such as f/2 which will give us a “shallow depth of field” (your subject will be in focus wile the background will be blurry). We do this by switching the camera to “aperture priority mode” (“A” on a Nikon, “Av” on Cannon) once in aperture priority we can scroll through the F stops  and choose whether you want a large or small aperture. Remember a large F stop such as f/22 will make a small opening thus making everything in focus, wile a small F stop such as f/1.8 will make only your subject in focus.

So if we want to take a photo of a flower where the flower is in focus and the background is out of focus, we tell the camera to shoot at a low F stop, around f/2.
If we were taking a photo of a landscape where we want everything to be in focus, we tell the camera to shoot at a large f/stop such as f/22.

Aperture to increase speed.

Lets say your shooting a sporting event and you need a fast shutter speed to capture your moving subject, or your indoors and you need your shutter speed to be fast enough so you don’t get blurry hand held shots. By having your aperture wide open (small F stop) you are allowing more light to enter your camera, which means you can get a faster exposure/shutter speed. This is when a good “fast” lens can be handy (fast refers to how wide the aperture can get)

In closing..

This is a brief description of how aperture effects the images you take. I advise you all to go out there and have a go at shooting in aperture priority mode, that way you can control and decide on the depth of field as you need it. My camera is almost always set to aperture priority, that way I can quickly choose to include the background to some degree or keep the detail in the background if I want to. I can also quickly set the aperture to wide open if im in a tricky low light situation.

Give it a try and feel free to leave a comment with any questions or post some of your photos on our forum!