Like ISO and shutter speed, aperture is known as one of the three “Pillars of Photography”. It’s important to understand all three pillars and how they work so you can use your camera to it’s fullest capabilities. No matter what kind of camera you shoot, aperture, shutter speed, and ISO all affect each other the same way. They form the basics of shooting.
What is Aperture?
Aperture is the opening in a lens that allows light to pass through. When you look through a lens, you might see what I’m talking about. The size of this opening affects how much light is allowed to pass through as well as amount of the image that is in focus.
How Does it Work?
Aperture blades in a lens work similarly to your own eyes. In the dark, our pupils expand to let in as much light as possible. While in the light, they shrink so we don’t let in too much light (essentially to prevent overexposing our own vision). Think about that when you think about how aperture works. We measure the size of the aperture by f-stops. The smaller the f-stop number, the wider the opening. It sounds like reverse logic, but f/2.8 is going to allow more light in than f/16. When you hear the phrase “shoot wide open” that means shooting at the lowest f-stop number (the widest the aperture blades can be).
Left: Shot at f/2.8 for a shallow depth of field to get just the cactus in focus / Right: Shot at f/16 to get the whole landscape in focus
Aperture can do more than just affect the amount of light passing through the lens. It also has a direct impact on the depth of field (DoF). The wider the aperture, the blurrier the background will be.
This background effect is called bokeh. Bokeh is quality of the out-of-focus areas in a photo.
Both the aperture and the focal length of the lens will affect the depth of field. Shooting at a wider focal length will give you less DoF, even if you are shooting wide open. However, if you shoot at a longer focal length, you will compress the image and get a much creamier background.
Shooting at a wide aperture with a shallow depth of field can be tricky. A shallow depth of field means less of the image will be in focus. You want to make sure the focal point of your image is sharp. It can be too easy to accidentally get someone’s nose in focus, but not their eyes if you’re shooting wide open! As always, play around with your settings and get comfortable working with aperture, I would suggest toying around with different focus points as well and get creative.
How Do I Change it on My DSLR Camera?
Where can you adjust the aperture on a DSLR Camera? If you’re having trouble finding out how to change your aperture, you can easily reference your manual or user guide. If you have no idea where you hid that thing, Googling it works just as well!
Top: Canon
Bottom: Nikon
Aperture is a key part to digital photography. You are given control of the depth of field as well as the amount of light that comes into an image. Understanding aperture unlocks so much creative potential! The next thing you should do is to go out and practice shooting on “Aperture Priority” or Manual mode on your camera, and have fun messing around with it!