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Aperture in photography. What it is and how to use it.

Aperture is the component on our camera that allows for our subject to be in focus while the rest of our background is blurred out.

Aperture refers to the opening in the lens that lets light in. This is kind of the eye of your camera. The amount of light let in is controlled by the f-stops on the lens that you are using.


In the previous blog we touched on "stops." Aperture is measured in f-stops and the numbers on your camera should look like this 1.8, 2.0, 2.2, 2.8, 3.2…. ect. When taking photos, the lower the f-stop is, the more light is let into your camera. How low the f-stop goes will completely depend on the lens that you are using. Some lenses only go as low as 4.0 whereas others have the ability to go as low as 1.2. The photo below shows just how aperture works. You can see the the lens is almost completely open at f/2 and almost completely closed at f/22.


If you have recently purchased your camera, you likely purchased it as a kit. In this kit they have provided you a lens. This lens is called a kit lens. These lenses usually only go to 3.5 or 4.0. I highly recommend purchasing a 50mm 1.8 lens. If you purchase it through Amazon or the camera website itself, they typically only run about $100. This will be one of your cheaper lens purchases, but I promise it is well worth it.


A lower aperture will also give you a shallow depth of field. A shallow depth of field is what creates that creamy, blurry background that everyone ooos and ahhhhs over! Believe it or not this "creamy, blurry background" has a name! It is called bokeh (pronounced bo-kah). Depth of Field refers to the distance between the closest object that is in focus and the furthest point of focus. (AKA DoF. We will touch base on focal plane and depth of field in the next portion of the series!) The distance can be increased or decreased by changing the aperture of the lens.



As a rule of thumb it is important to keep your aperture set to the same number of faces you are shooting. If you are shooting 4 people, keep your f-stop at 4.0 or higher. If you are only shooting one person, I suggest only going as far down as 2.8 when starting out. Just because your lens can go as wide open as 1.8 doesn’t mean you should shoot that wide open. If you do and you aren't standing far enough away your image will turn out blurry.

Someone once told me that aperture is like looking through a straw. When you look at an object up close through a straw, you only see a small portion of that object. If you continue looking through the straw and taking steps away from the object, you will eventually see the entire object. Aperture acts the same way! The lower your aperture, the less your camera is able to "see". The higher your aperture the more it can "see". If you wanted to shoot at 1.8 with a family of 4 you would need to make sure you were standing a good distance away to get them all in focus. You would also need to be sure they were all standing on the same focal plane. This means that your subjects all need to be in line with where your focus point is landing. It's not impossible, but it is much more complicated! As a beginner it would be best to keep your f-stop at 4.0 or higher depending on your family size!



Join me next time to understand focal plane and depth of field.

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