Foundations of Photography: The Exposure Triangle
There are three settings that are used to create a proper photography exposure. They are Aperture, Shutter Speed, and ISO.
The camera’s Aperture controls how much light enters the lens during an exposure. It is much like the iris in your eyes. When it is open all the way, it allows the most light in. When it is closed (also called stopped down) it allows less light through your lens. The higher the number, called an f-stop, the less light that can come through. The higher the f number, the more light that can come through. Your aperture also controls your depth of field, which will determine how much of your photography or photograph is in focus.
Shutter speed controls how long the camera’s sensor is exposed to the light. The less light available in your scene, the longer your shutter will need to be open. Shutter speed can also be used to create cool effects using a long exposure or freeze action using a fast shutter speed.
ISO controls how sensitive your camera’s sensor is to light. The higher the ISO, the more sensitive the sensor is and vice versa. We use this setting in situations where you need a faster shutter speed at a given aperture
Let’s say you are trying to photograph a basketball game indoors, you want a fast enough shutter speed to freeze the action. However, there isn’t enough light reaching your sensor at the widest aperture of your lens. You would then bump up your ISO.
Another situation is when you want maximum depth of field at an aperture of f/22 and are trying to shoot handheld. You want a faster shutter speed to eliminate motion blur, so you would have to increase your ISO.
Setting these settings correctly is largely dependent on what you are trying to achieve. If you want a shallow depth of field, then a wide-open aperture will be your main concern. If you want smooth, flowing water, then you will want a slow shutter speed, which will require a higher aperture number.
Now that you have a basic understanding of how the exposure triangle settings work together, contact us for all your multimedia needs!