ISO, Aperture, and Shutter Speed

Photo by Warren Wong on Unsplash

When dealing with Photography, it is crucial to know and understand the “Exposure Triangle.” The Exposure triangle consists of ISOs, apertures, and shutter speeds. These determine the exposure of your image when you are taking a photo. It also determines the overall appearance of your photo. You have to control and adjust each setting in order to get the result you desire.

ISOs control your camera’s exposure, or in other words, its sensitivity to light. A higher ISO produces a brighter picture than a lower ISO. This means your ISO would be at 1600 and up. You typically need a higher ISO if you are in a darker area. ISOs also determine the amount of noise your photo has. There is more noise in higher ISOs than in lower ISOs, making the picture look grainy. Lower ISOs are shot on camera with numbers like 100 or 200. These produce less noise. Depending on the camera you are using, there is an option to set your ISO to automatic. So instead of changing the ISO settings manually, the camera has it set for you. The photo below demonstrates a low ISO of 100.


Aperture determines how much light you let in the camera. When you hear the word “f-stop” know that it is referring to aperture. High f-stops, such as f/16 or f/22, give off a greater depth of field, allowing less light in the lens. This also means you’ll be getting a darker picture. Lower f-stops, such as f/4 or f/5.6, give off a narrow depth of field, allowing more light in and giving you a brighter picture. The picture below was shot with an f-stop of 7.1, keeping the first three books in focus and the rest blurred out.


Shutter speeds measure how long you expose light to the image sensor. For a slow shutter speed, you get a higher exposure and for a fast shutter speed, you get a lower exposure. If you are using a high shutter speed when taking a picture of a moving subject, for example, flipping your text-book pages, you would get a less of a blur. However, you would get more of a blur if your subject was moving and you used a lower shutter speed. The photo below shows a shutter speed of 1/100 sec. Notice how the blur is seen due to the slow shutter setting.


If you don’t understand these three variables of photography, chances are your photo could come out over exposed, under exposed, blurry, etc. All these factors are due to what ISO, aperture, and shutter speed you are on. It may take a while to get used to adjusting your settings properly and tying to get a good exposure, but overtime your technique will improve, as will your photos. It’s all about practice.


Photography Basics 101

The Exposure Triangle