Last Friday, I wrote a post about three things I do for good exposure. This blog post is going to talk about three functions of the camera that can impact exposure. It’s all about the exposure triangle today!!
There are three aspects to the exposure triangle: ISO, aperture, and the shutter. Before I talk about how these three things can work together to really get you that awesome exposure, I’m going to break them down for you.
ISO is how sensitive the sensor, in your camera, is to light. If you have your camera set on a low ISO, you have low sensitivity (which is a finer photo). If you have your camera set to a high ISO, you have a high sensitivity to light (which equals more “noise,” also known as “grain.”). Basically, think of ISO as how much light you are letting into your camera – low ISO, less light; high ISO, more light.
The photo on the left has a high ISO (6400), and the photo on the right has a low ISO (200).
Aperture is how big the opening of your lens is. The way I think of it, is how much are you trying to focus on? Aperture is usually referred to as the f-stop. It’s the part of your camera where you see f/number. The logic behind aperture feels backwards, but once you get use to it, it becomes natural to think about. If you have a large aperture, the f-stop is a really small number (1/1.4, 1/1.8, 1/3.5, etc). If you have a small aperture, you have a high number for the f-stop (1/8, 1/11, 1/22, etc.).
Aperture is also related to depth of field (DOF). DOF is how much of your photo is in focus. How does relate to aperture? Well, if you have a small depth of field (less focus), you have a small f-stop. If want a large depth of field (more focus), you have a high f-stop. Remember, small f-stop means a large aperture, and a high f-stop means you have small aperture.
Here are two photos to help demonstrate:
Photo on the left is shot at f/1.8, and the photo on the right is shot at f/11.
The shutter speed is how long your shutter is open and is measured in seconds. A slow shutter speed can result in more light and potentially more blur due to hand shake. A high shutter speed can result in the opposite.
Photo on the left has a shutter speed of 1″, and photo on the left has a shutter speed of 1/60.
How do these work together?
Essentially, you can’t change one of these three elements without impacting the other two. If you change your shutter speed to a really fast speed, then your photo may be too dark, so you may want to up your ISO, and lower your aperture. If you are shooting in manual, you have complete control of all three of these elements. If you are shooting in aperture priority mode, then you only have control over the aperture, and the camera adjusts the other two accordingly. The same with shutter priority. If you only have control over the shutter speed, the camera will adjust the other two.
My biggest suggestion is to play around in shutter and aperture priority modes, just so you can see how all three of them relate and change based on the other settings. It’s neat to figure out on your camera.
Here are a few quick tips to try out in different situations:
– If you’re shooting in a dark room, increase your ISO.
– If you’re shooting in a really bright situation, crank up your shutter speed and lower your ISO, so that it doesn’t blow out your photo.
– I really like having a small depth of field, so I shoot at f/1.8 or f/2. For every person you add into a frame, you want to increase your aperture by one stop for each person. Typically, I’ll shoot at f/3.5 for three people or more. It’s also important to place your focus point on the person closest to you, because the camera can create focus behind that point, but not in front of it.
– You’re in a dark room, but don’t want to increase your ISO? Get out a tripod, and use a slow shutter speed, and a small f-stop.