The Exposure Triangle is the fourth and last part of our beginner fundamental series. I recommend that you read the other parts before reading this.
Up til now we have been introduced to ISO, Aperture and Shutter Speed. Understanding what each of them are, is important for you to take control over your camera. To fully be able to use manual mode, you also need to understand how these settings work together. This is known as The Exposure Triangle.
Since we have already looked into the elements of the exposure triangle, this article will be pretty short and basic, just to sum up each setting and how they function together. For further reading on each setting, see the previous parts of this series.
The Exposure Triangle
As you might have understood The Exposure Triangle consists of Shutter Speed, Aperture and ISO. Each of these elements have great impact on both each other and the final image.
In the previous articles I have used the comparison between a camera and a room with curtains, but to explain how they all work together lets use another example.
Imaging that you wish to fill a room with water. On the wall you have a window where the water enters. To let water in you need to open the window, this resembles the Aperture. The more you open the window, the more water lets through.
The duration you keep the window open resembles the Shutter Speed. So how does this two impact each other? Let’s say that you wish to fill the entire room with water. If you have a small opening in the window, it will take longer time until the room is filled. If you decide to open the window to the fullest, it will take less time to let all the water in.
So what about the ISO? This might be where things get a little more complicated. Let’s say that you wish to get rid of all the dirt in the water when it comes into the room. You do this by installing a strainer inside the window. A low ISO such as 100 resembles a strain with small holes, that removes all the dirt from the water. However since the holes are so small, you will need more time for the water to fill the room (longer shutter speed). If you choose to have a strainer with big holes, the water gets in much quicker. But by having bigger holes, you also let in more dirt and reduce the water quality.
I’ll translate that into photography terms to make it even clearer. A higher ISO let’s you use a faster shutter speed, on the expense of your images quality. High ISO results in more grain and noise.
If you have not read the previous articles in this series, you can find more in depth information about each settings in these links:
Part 1: Introduction to ISO in Landscape Photography
Part 2: Introduction to Aperture in Landscape Photography
Part 3: Introduction to Shutter Speed in Landscape Photography
Part 4: The Exposure Triangle