Let’s start with a story. I have found myself on the sidelines of a University of Tennessee football game in 2013. My mission: get amazing photographs that can be used in sports articles. No pressure, right? The game started around noon and it was a beautiful, sunny day. I knew that I wanted to use a fast shutter speed so that the athlete’s movements wouldn’t be blurry, so I set the shutter speed to about 1/500. I also knew that I wanted the background of the stadium to be out of focus so the athletes will be the main focal point of the photograph, so I set the aperture as wide open as it would go to about f/4. My ISO was still set to a previous shoot at ISO 800. As the teams got ready to run a play I brought my viewfinder to my right eye and clicked away. After the play, I looked at the LCD screen on the back of my DSLR and WOW, that was the brightest photo I have ever taken! What a terrible shot!
So, what happened? Let’s break it down.
The aperture in your camera is a group of tiny blades that open and close based on the size you set it to. You’ll hear a lot of photographers talk about small apertures and large apertures. They are referring to how big of an opening there is in the middle of the blades. A large aperture represents a large opening. A small aperture represents a small opening. The larger the aperture opening is in the middle of the blades, the more light is getting into the camera.
If you take a photograph with a large aperture and the photo is too bright, you would fix it by using a smaller aperture. Apertures are measured by f-stops. An f-stop of f/4, like I was using at the game, will have a very large opening in the middle of the aperture blades. An f-stop of f/22 will have a very small opening in the middle of the aperture blades.
The aperture also controls the depth of field, which is the amount of distance that is in focus in a photograph. An f-stop of f/4 will have a very shallow depth of field and will make the farther distances from your subject out of focus. An f-stop of f/22 will show far distances more in focus. Take a look at the image below so it will make more sense.
The shutter is the amount of time your camera is taking a photograph. For example, in the story above, my shutter at the game was around 1/500. That means my camera was taking a photograph for 1/500th of a second. That’s a fast shutter! A faster shutter speed like this will freeze fast movement in a photograph. However, when you slow your shutter speed down you will start to see blur wherever there is movement. I wanted to freeze the action of the football game so I was using a fast shutter speed.
Shutter also controls how much light is getting into the camera. With a faster shutter your camera it taking a quicker photograph, thus less light will enter the camera. If you are using a slower shutter speed such as 1/30th of a second, more light will enter the camera. Also, when you use a slower shutter speed you are risking a blurry photograph from your hands moving. I recommend using a tripod with anything below 1/60th of a second. If that doesn’t make sense, use the image below to better understand shutter speed.
ISO is the third way that you can control light. ISO determines how sensitive the camera sensor is to light. ISO is also pretty easy to grasp. A lower ISO number, the less light . So, an ISO of 100 is not going to let the sensor see much light. An ISO of 2400 is going to allow the sensor to see a lot of light.
The only problem with ISO is the higher you go, the more the photograph will look grainy. A high ISO can cause what is called noise. It almost looks like there are tiny splotches of dust all over the photograph. So, lower ISO means less light and less noise. A higher ISO means more light and more noise. Here’s an image explaining the ISO, light, and noise.
Now that we understand aperture, shutter and ISO, let’s visit my day on the football field again. I think we are at the point in the story where I have ruined the photograph, my photography career, and will eventually end up homeless. But wait! There’s hope! I understand how aperture, shutter and ISO work together! Since I know I want to keep my aperture wide open to create a lot of depth of field, I can either increase the shutter speed to let in less light and still be able to freeze motion in the photograph, or I can decrease the ISO. Since it was a very sunny day and I had a fast enough shutter to freeze the action of the game already, I decided to decrease the ISO. Presto! A perfectly exposed photograph and my life is back on track!
Once you understand how to balance light with aperture, shutter, and ISO to get a proper exposure, you can use your camera in manual mode with ease! Just remember to practice and you will continue to get better! If you are still confused, CONTACT ME and I’ll help you out!