If your camera lens is the eye to your camera, than the Aperture is the pupil of the lens. The Aperture is the opening within your lens that regulates how much light enters the camera. If too much light enters the camera, the camera can be blinded. Just like how the human eye adjusts to when it is bright out, the pupil closes up really small so just a tiny amount of light enters the eye, but if it gets dark out, your pupil will open up nice and large to allow in as much light as possible. The Aperture in your camera lens works exactly the same way.
But there is a lot more to your aperture than just being an opening inside your lens. Adjusting the aperture has a dramatic effect on the final look of your image.
The size of the aperture is measured in F-Stops. The lower the f-stop number, the larger the size of the aperture opening, and the smaller the depth of field will be. I know this sounds backwards and you’d think that the lower number would mean the aperture opening is smaller but this is incorrect.
But with practice, you will start to see what the difference is between an F 2.8 and an F22 aperture and how they change the look of the image. Before you know it, adjusting the Aperture will be second nature. You won’t have to think twice about what f-stop does what, Now you can focus on your what your taking pictures of, instead of fiddling with the camera.
How Aperture effects the picture
- Increases or decreases how large the depth of field is.
- Creates that soft background that makes your subject pop.
- Increases or decreases how sharp the photo is.
- Increases or decreases the amount of light entering the camera.
- You can shoot at a faster or slower shutter speed depending on what aperture you choose.
- Creates cool little star effects from any light sources in the picture.
If you increase the size of the aperture, you increase the amount of light that is entering the camera, but at the same time, you also decrease how large the depth of field is. That means the background behind your subject will be out of focus and make your model pop off the background. This can make for some beautiful portraits.
But if decrease the size of the aperture, less light will enter the lens, and because a smaller aperture increases the depth of field, more of the scene will be in focus. It is a balancing act deciding how much light you need vs. how shallow you want the depth of field to be.
Aperture and Depth of Field
This animation shows how the Depth of field increases the higher you raise f-stop number goes. You will also notice another side effect of increasing the f-stop, the lights will create a star burst effect the higher the f-stop goes. At f2.8 the shape in the background is blurry. At around f5.6 or f8, the object finally becomes sharp. The Depth of Field is now large enough that it includes the foreground and background.
Even if you are set to f22, your lens still may not reach the full depth of field you want. You can use focus stacking to stack multiple pictures together to create a picture with everything in focus. Learn how to Focus Stacking here.
Aperture and Exposure
The aperture does not just effect the Depth of Field, it also controls how much light enters the camera. As the aperture is adjusted, the aperture hole changes size within the lens. The lower the number, the larger the hole, the more light enters the camera. . The higher the number, the smaller the opening, the less light enters the lens.
On a bright sunny day, you can easily shoot at any aperture. But if you are in a low light situation like a wedding or out with friends, you will need to shoot with a lower f-stop to collect the most amount of light possible, otherwise you must add a light source to the scene using a flash, or turning on some lights. But Nothing spoils the mood more than a bunch of flashes popping around the room or flipping on the overhead lights.
Churches can be very dim, so in order to not miss any of the action, wedding photographers absolutely rely on their fast lenses that allow them to shoot in low light with a low f-stop. It would be terrible to miss the First Kiss because your lens was not fast enough so you got a blurry shot of the bride kissing her groom. A wedding photographer is paid to document everything and to not miss anything during the wedding. Having a fast lens is an absolute necessity for wedding photographers.
If you are really determined to become a better photographer, it is required that you learn about the exposure triangle. The Exposure Triangle are the three elements (Aperture, Shutter Speed, and ISO) that all contribute to how the camera creates an exposure.
Now get out there, set your camera to Aperture Priority and see for yourself how adjusting f-stop changes the look of the image. You can take your average pictures to amazing pictures by using a creative depth of field. Have fun!