On digital cameras, you will notice one of the things you can adjust is called the aperture. The aperture is the opening in a lens, which lets light enter the camera. Adjusting this can affect and change your depth of field. Depth of field is the focus on a subject, or an entire shot. Depth of field can rather have a subject in focus, and make a viewer see the importance of the subject while having the background blurry, or have an entire shot focused, helping the viewer see an entire scene. When photographers talk about the “depth of field” in an image, they’re referring to how much of the picture they choose to have in focus. The adjustment of depth of field can make your subject pop out and make it more important in a image. You can adjust your depth of field by adjusting the aperture. Like your eye, a camera lens has an iris inside that can open or close to let in more or less light. You control the size of this hole, or aperture, by changing the aperture setting, which is measured using a scale of f-stops. The larger the aperture, the shallower your depth of field will be, meaning a smaller portion of your image will be in focus. The smaller the aperture, the deeper your depth of field will be, resulting in more of your image being in focus. When adjusting your aperture, you would look at the f-stop and adjust it according to what it reads. A lower f-number such as 2.8 will have your lens wide and have less of a depth of field. With low depth of field, your image will come out to be shallow. A shallow image is when a smaller portion of your image will be in focus, such as a subject or an object of interest. A higher f-number such as f-11 will have a tiny hole in the lens, giving more depth of field and focus. With a larger number and a smaller lens, more of the image will be in focus giving the entire photo it’s focus.
Fortunately for us, most camera have aperture control so we can choose rather we want a shallow or deep depth of field. If you ever get your hands on a camera with aperture settings, choose to toy with it for the perfect image. Some examples for shallow depths of fields is when you are shooting a portrait. It is nice to have a shallow depth of field so that you can focus on a person’s face or subject of interest. Shallow depth of field could also be very helpful any time you need a way to separate a subject from a busy background, for example when you are street shooting, event shooting, or any other situations can benefit from a reduction in depth of field. For deep depth of fields, you typically use this for landscape shooting. When wanting a larger photo, you would choose a small aperture, which will be shown by a larger f-number. Product shots, certain types of still life images, and any shot where you need to see both foreground and background details will also benefit from deep depth of field. If you have a lens that can open up very wide, this could be called a fast lens, you’ll want to think about how shallow you want the depth of field to be. If you have a very fast lens, and you open it up to its largest aperture, you might have a difficult time focusing. This will make your backgrounds go too soft and make it difficult to keep the correct parts of your image in focus. So the main thing when talking about depth of field is the aperture. A low f-number such as f2 will give you a large lens with a very shallow depth of field, and a strong subject focus. A larger f-number such as f8 will give you a much smaller lens, with a deep depth of field, usually used in landscape shooting.