The Exposure Triangle – Learn More About It

If you are interested to learn more about exposure or if you are keen to know about the right way of experimenting with your digital camera’s manual settings or how to use its Auto Mode, then you should learn about the main three elements to consider, which are collectively called the exposure triangle. Every one of these elements relates to light and the way it penetrates and interacts with your camera. These elements are; ISO, Aperture and Shutter Speed. Many of these elements can even enable you to take bird photography with smart phone, sometimes it takes additional tools but knowing the this triangle will help you accomplish it.

ISO is defined as the digital camera sensor’s measure of its sensitivity to light. The Aperture is the size of the lens opening when a shot is taken. Lastly, the camera’s shutter speed is the measurement of the time the shutter is open.

The image’s exposure is effectively worked at these elements’ intersection. Therefore, it is important to understand that any change in any one of these three elements will surely have an effect on the other elements. It simply means that you should never isolate a single element; rather you should always put all three into consideration, at all times.

Three Symbols for Understanding the Exposure Triangle of Digital Photography

A lot of people define the connection between these three elements with the use of symbols or metaphors for better understanding. Here are three metaphors:

The Window

To understand this symbol, you should try to imagine your digital camera as a window with its Shutter opening and closing.

The Aperture is the windows size. A bigger size is going to allow more light making the room perfectly brighter.

The amount of time that your window’s shutters are open is the Shutter Speed. The longer amount of time they are left open, the more light is going to enter.

Think of yourself inside the room and you have sunglasses on. Let’s say your eyes are desensitized, this could mean low ISO. To increase the amount of light penetrating the room, what you need to do is to increase the amount of time that the shutters are open; meaning the shutter speed should be decreased. You can also open the window more, which is similar to increasing the aperture, or you can also simply take your sunglasses off, equivalent to making higher ISO.


This is the second metaphor, wherein you can imagine the exposure of your digital camera as if you are getting tanned by the sun. You can think of your skin type as ISO rating.

Shutter speed can be deemed as the length of time that you are spending out in the open. The more time you are exposed in the sun, the more chances that you will get a tan; don’t just spend too much time if you don’t want to be over-exposed.

The sunscreen that you are applying to your skin is the Aperture. The main purpose of a sunscreen is to block out the sun at various levels depending on the lotion’s strength. If you use a high strength suntan lotion, then you lessen the amount of sunlight penetrating through your skin. This is ideal for people with sensitive skin.  Using a lower strength sunscreen lotion can be compared to slowing down of the shutter speed and/or decreasing the ISO.

Garden Hose

This third metaphor illustrates the aperture as the hose’s width, the shutter speed is the length of the time that the hose is left on, and the ISO is the water pressure as it goes through the hose.

Understand them All Together

It may take some practice to master the art of exposure. But if you are decided to know that you can be a highly experienced photographer in no time at all. All it takes is a little vigilance, some amount of perseverance and a whole lot of experimenting and tweaking on your camera’s settings.

The best thing about a digital camera is that it can be the perfect trial tool for learning more about exposure. It is safe to take as many shots as you want for free. It also can be used for shooting in Auto and manual mode.

Photo Credit: Sadie Hernandez