Greetings Designers,
Today's topic is on the Exposure Triangle (also known as the Photography Triangle) and how it can help you achieve the perfect exposure for your projects.
First off, we need to define the key elements that make up the Exposure Triangle:
- Aperture
- Shutter Speed
- ISO
Aperture
Aperture (also referred to in f-stops) controls how much light is entering into the sensor. Inside your camera lens, a section of overlapping blades slowly open and close to throttle how much light is hitting your camera's sensor. For example, if you set your camera lens to have a wide aperture, this provides the most light for the sensor. This results in a shallow depth of field, where the subject is sharp but the background is blurred (commonly referenced as bokeh). The opposite happens when you have a narrow aperture. This decreases the amount of light entering the sensor, resulting in a deep depth of field and most of the scene being in focus.
But don't get confused with how aperture is labeled on lenses (like me). The number on your lens that reads f/1.4, f/2.8, or f/5 shows the widest possible f-stop that lens can achieve. So a common rule of thumb is the lower the number, the more light that can enter the lens. The higher the number, the less light that can enter. Some lenses even have variable apertures that depend on what focus range you're at (typically labeled with a range. So if you are at your maximum focal length, the lowest aperture you can set your lens to changes).
Shutter Speed
Shutter speed controls how long the camera's shutter remains open, allowing light to hit the sensor. Increasing or decreasing your shutter speed can have varying affects on the way the image develops. If you have a high shutter speed, this enables your camera's shutter to close faster, allowing you to capture subjects in motion while keeping them sharp and in focus. And if you have a low shutter speed, your shutter stays open for longer and creates motion blur for moving subjects (this can be ideal for capturing time lapses or even light trails). Having a slow shutter can also be useful for capturing astrophotography, since you're letting tons of light enter the sensor.
ISO
ISO controls your camera's sensitivity to light. When the ISO number is increased, the sensor is compensating for the lack of light and adding artificial light to the image. Within a reasonable range, this doesn't distort the image enough to be visible (depending on how old your camera is). However, if you continue to introduce more ISO into your image, you will see noise/distortion. A good rule of thumb is to increase your ISO value when you run out of other options. Some newer cameras actually come with a native ISO built in. Shooting on your camera's native ISO allows you to get the cleanest image possible!
So for a quick recap, Aperture, Shutter Speed, and ISO work together to help you get the perfect exposure for your photos. Aperture controls how much light enters the lens and affects depth of field, shutter speed determines how motion is captured, and ISO adjusts the sensor’s light sensitivity. Balancing these three settings lets you take sharp, well-lit images while also giving you creative control over things like background blur, motion effects, and image clarity.
Hope this helps!
-Michael