Exposure and Your Photography By Elijah Fisher

Exposure and Your Photography

In this article we are going to go over the exposure triangle. I want to preface this by saying that the exposure triangle is a concept that is meant to help people understand that there are three aspects to a properly exposed image and to get an idea of what those aspects do for the photograph. For instance, ISO, which measures the sensitivity of the image sensor, is not free extra exposure; there is a down fall which is digital noise. I will explain more about this later.

There are three-dimensional ways that you can use the three different parts of photography and have a system where you can plot points and show the brightness of a given image using the aperture, ISO, and shutter. This can get complicated and although it is outside the scope of this article, you might want to learn more after this introduction. For this article, though, we will discuss it on beginner terms from a triangular perspective.

There are many different examples of the exposure triangle. I choose some simplier images to help you understand what each of the sides of the triangle does. If you want to find triangles that have more or less detail and information on them just look it up online; you will find many great examples.

Written by Elijah Fisher Photos by Elijah Fisher

First, let’s go with the aperture. The aperture is like the iris of a human eye. It constricts and expands to let in more or less light. The part of the camera that contains the aperture is located in the lens. Whenever you switch lenses on a system that allows you to switch lenses, you will use different apertures. Some lenses have an aperture of f4, some have f2.8. Lenses that do not zoom, prime lenses, can be bought with apertures all the way down to f1.4, or even f1.2. Some zoom lenses that are bought with the camera have a variable aperture. The aperture changes size as you zoom in. This a common option; more expensive lenses do not change like this. A common aperture for a kit lens is f3.5 to f5.6.

er than an f4 lens. This is critical to remember as it can get confusing when you are trying to remember the three different parts of exposure.

The impact that this has is that the wider open the lens, the smaller the number the f-stop and the more light that is let into the lens. We already went over how this would brighten your exposure. When light floods into the lens it is not as focused. The area of your photograph that is the focused will be sharp. But areas in front of and behind your focal plane will be much blurrier than if you used an aperture that is more closed, like f8 or f16. This causes the light to have to move through the lens in a more direct path, hitting the sensor in a more focused pattern. This can be used artistically to have a more focused shot, causing more background blur. The general consensus is that you would shoot with your lens as wide open as possible most of the time. You normally only shoot with a tighter aperture. This causes the light to have to move through the lens in a more direct path hitting the sensor in a more focused pattern. This allows for artistic leeway to have a more focused shot or to create more background blur. The general consensus is that you shoot with the lens as wide open as possible most of the time. You normally only shoot with a tighter aperture if your scene is extremely bright and you cannot adjust with the shutter speed or you are looking for a wider field of view. Macro-photographers often use larger apertures to get as much detail and focus as possible when taking pictures of small objects.

Beverly Torres, a distinguished macro-photographer from Unique Views says, “Using a large aperture is what can get the entire flower or bug in focus when you are very close to your subject.”

Aperture does play a large role in macro-photography, larger than in normal portrait or event photography.

Shutter speed, on the other hand, is a little bit simpler. The shutter is a part of the camera that

physically moves in front of the sensor to allow light to hit it and be digitally processed. The shutter speed is measured in fractions of a second, indicating how long the sensor is exposed to the light through the lens. Shutter speeds can range from manual exposure of up to 30 seconds to 1/4000 or even 1/8000 of a second. As you might expect, because this is a bit more straightforward, the longer the shutter is open the more light hits the lens. In its entirety, it is easier to understand than exposure. The way this affects the exposure triangle is that the longer the shutter is open the more blur you will see in your image. This is not the same type of blur that you would see because of aperture; this is motion blur that is either caused by your subject moving or the camera itself moving. The faster the shutter speed the more the motion will be frozen. For most purposes 1/500 of a second will freeze motion almost entirely. Below 1/60 of a second you will begin not to be able to see a person’s features as they are walking fast or running in your frame. This is also the point where hand vibration becomes an issue. A good rule of thumb is to always have your shutter speed at twice the focal length of your lens. If you are shooting a 50 mm prime then you want shutter speed to be at 1/100 of a second. If you are shooting a 200 mm lens then you want your shutter speed at 1/400 of a second. This is a rule that can be broken however, you might have a steady hand or a camera or lens with image stabilization. A good image stabilization system can help make a difference to this rule. In general, a sharper image via shutter speed is good; an option to be able to bump your shutter speed up is usually appreciated. This makes it so that shutter speed is often the way to darken

an extra bright image. Usually, you want to keep your lens fully open to get as much depth of field as possible, so shutter speed is the obvious answer for this. Shutter speed is easier to understand and utilize than aperture is- but it is no less important. If you are further interested or want to see some examples look it up online and see what you find. individual pixel is able to read out more accurately. Although this does not make too much sense for most beginners who are learning about the exposure triangle to worry about, if you are buying your first camera and you know you are going to be shooting a lot of night time or low light photography, such as at a wedding venue, then you might want to consider getting a camera that has good reviews for use in low-light.

ISO is possibly the easiest to understand. ISO is the digital sensitivity of the sensor. I am not sure what happens scientifically, but when you boost ISO the sensor becomes more sensitive and it heats up. Heating up can cause some of the sensors to get misreadings and a pixel will come out a different color, often in the red or purple spectrum. This always happens to a degree, even when shooting at a lower ISO. But when you raise ISO past 1000, or higher for some cameras with better sensors, you will begin to see a larger amount of ISO- to the point where the image can become unusable in most cases. So if you have not realized it yet, the lower the ISO the less sensitive the sensor is and the less light it takes in. Conversely, the higher the ISO the more sensitive it is and the more light it takes in. Steve Morris, a photography instructor from Tampa Photography Group says, “There are many different aspects to consider when buying a camera, but that should not stop you from using the one that you have, even if it is your phone.” Finally, the only way to really apply what you learned here, and in other places, is to practice. Do not be afraid of taking pictures without knowing exactly what you are doing. That is how

There are ways to negate a higher ISO sensitivity problem. First of all, with any camera you can run it through software that will try to digitally erase the sensitivity noise, which works to a degree. We can also take away some of the detail in the image. Some cameras even have an ability to process the image in this way when it outputs a jpeg. The second way to deal with this, and something to consider, is that some cameras, especially ones with larger full-frame sensors, are more sensitive. They can use a higher ISO and have cleaner images because they are designed so that the sensor does not heat up as quickly, so each I learned. I bought a DSLR without knowing what the exposure triangle does. Looking back, it was a huge learning experience and I still use that camera as my main camera and use it to its maximum capacity all the time. Giles Hooper, Lead Photographer at Grace Family Church says, “You need to shoot all the time so you can continue to gain experience in photography.”