Perhaps you’ve seen a photo of a mountain scape in which all things, the flowers in front, to the peaks in the back, are sharp and in focus. You may have also seen a portrait of a person, where their face is sharp, but the background is completely blurry. The difference in the depth-of-field between these examples is a result of changes in aperture!
The word “aperture” describes an opening, hole, or gap in something. In every camera setup, the opening (aperture) is found within the lens itself. Some lenses can open very wide, and others open up modestly. Nonetheless, most modern cameras (such as any DSLR) have the ability to control the range of aperture values available in the lens being used. Have you ever noticed a setting on your camera that reads, “f3.5, f13,” etc.? These are f-stop measurements, and they determine how much light is let into the camera through this opening, and the depth-of-field of the picture. This control provides a photographer with a technical and artistic ability to manipulate photographs.
The relationship between f-stop, the size of the actual aperture, and the depth-of-field can actually be very confusing to understand at first. When you lower your f-stop number, you are essentially increasing the size of the aperture, the opening in your lens, and allowing more light into the camera. At the same time, however, you are decreasing the depth-of-field. So, if you open up the aperture more to allow more light, you are simultaneously decreasing the amount of area in the photo that will be in focus. This can be very useful in situations in which you are shooting in low-light areas, such as a dark concert, or if you are shooting portraits and only want the person’s face in focus.
Although allowing more light can be important, as can be blurring out your background to isolate your subject, in some cases, it may be more important for you to capture detail in an entire scene from front to back. In this case, increasing the f-stop number would be a better choice. When this is done, the aperture’s size is decreased, and less light is allowed into the camera. Although less light enters the camera, the depth-of-field increases, meaning that more detail from the front to the back of the scene will be captured. This can be especially useful in cases where you want to take a photo of a scene with a beautiful foreground that leads into a distant background.
Incorporating an understanding of aperture and playing around with this setting can be really fun in photography! If this concept interests you, try it out on your own camera. A great way to do this is to set your camera to aperture priority mode (Av on the camera dial). As I mentioned in my last photo tip on shutter speed, there are also apps for your phone that allow you to manually determine the settings your photos are shot with! I encourage you to mess around with this concept, and also put your understanding of it together with the concept of shutter speed using manual mode (M on the dial)!
What’s Aperture? Photo Tips by Austin
Wide Aperture (f1.4) – More light, less focus
