Exposure is the foundation and one of the most basic concepts of photography. Every aspiring photographer needs to learn how to use it in their photographs.
Exposure can either make or break your photography and hence, it is crucial to get it right. When you understand how to expose an image effectively, you will be able to capture photographs with the ideal brightness and high level of detail.
Many beginners though, struggle to grasp this fundamental concept of photography. In this guide we will be helping you answer the question; what is exposure in photography?
What is Exposure?
In photography, the amount of light that reaches your camera sensor or film is called exposure. The final look and brightness of the image will be determined by the amount of light that is collected by your camera.
To capture an image with a predetermined brightness you need to get your exposure right. When your exposure is spot on, you will be able to capture all details, in both shadows and highlight areas.
When your camera sensor does not receive enough light, the exposure effect is called underexposure. Photographers often use the phrase “crushed shadows” or “crushed the blacks” to describe such an effect. This is because when a photograph is underexposed, we get no information about the darkest areas of the image, and details in shadows aren’t as clear as they should be.
In contrast, when your camera sensor captures excess light, the effect is known as overexposure. The term “blown out highlights” or “burned out highlights” is often used to describe the effect. When a photograph is overexposed, we have no information about the brightest areas of the image, and the highlight areas are less detailed.
The Basic Exposure Settings
The exposure value of your image is determined by three basic camera settings. Shutter speed and aperture are the two camera settings that affect the actual “luminous exposure” of an image. Furthermore, your camera ISO also affects the brightness of an image and is equally important to consider.
All of this may sound basic, but exposure is a concept that even advanced photographers struggle with. Clicking a properly exposed photograph is not just about ideal brightness. It involves a delicate balancing act of these three settings so the overall photograph, from the depth of field to the sharpness, looks good.
With the right camera and a bit of practice, you will be able to master your exposure, and improve the overall quality of your photography.
Exposure and Camera Aperture
The aperture is basically an opening in your camera lens that determines how much light enters your camera. Similar to the pupil of your eye, the aperture of your camera can widen and shrink to manipulate the amount of light reaching the sensor. This is the reason exposure is dependent on the aperture of your lens.
If you use a wider aperture setting, the camera lens will allow more light to enter and reach the sensor. This will result in a more exposed and brighter image. Conversely, using a narrower aperture setting will block light from reaching the sensor, in turn giving you an image that is darker and less exposed.
Exposure and Shutter Speed
Shutter speed in simple terms is the amount of time your camera takes to click a photograph. It can range from anywhere between 1/100th of a second to 30 seconds. It is basically the amount of time for which your shutter remains open.
The longer the shutter speed, the more light you will allow your camera to capture, giving you a brighter image. A shorter shutter speed will not give your camera sufficient time to capture plenty of light, giving you a less exposed image as a result.
Exposure and Camera ISO
In simple terms, ISO is the level of sensitivity of your camera to available light. ISO is not directly related to the luminous exposure of your photograph, but works artificially to amplify the light in the image that has already been captured.
A higher ISO setting will brighten up your image, giving you a more exposed image, while a lower ISO setting will give you a less exposed image, considering the other settings are constant.
Balancing Exposure in Photography
Now that you know the factors that affect exposure, it is important to learn how to balance the three to give you an ideal exposure value. This is known as the exposure triangle. An exposure value(EV) of zero is ideal. If your exposure value is less than 0 you will get an underexposed image, and if it is greater than 0, the image will be overexposed.
Depending on the situation, you will need to play with the three settings to get a perfectly exposed photograph. Here, we will be giving you some examples to help you out.
For example, if you’re shooting a landscape shot in broad daylight, you would know that you’d need to have an aperture around f/11 to get a proper depth of field. Your ISO must also be around 100 to reduce digital noise. Hence, to get a proper exposure you would need to play around with your shutter speed.
If you are shooting a night scene, you would need the widest aperture, around f/2.8 to capture as much light as possible. In order to capture sharp stars, your shutter speed would also need to be low. Hence, to get the perfect exposure you would need to adjust your ISO settings.
For a fast moving object such as a flying bird, a fast shutter speed would be required, and you would also need a low ISO setting to get rid of digital noise. Hence, you may need to widen your aperture so that your photograph is not underexposed.
Although many photographers struggle with getting the right exposure, with practice you will be able to carry out this delicate balancing act with ease. I hope novice photographers now have a better understanding of what is exposure in photography through this article.
As photographers, it is important for us to get out there in different situations and just click photographs. It is essential to get used to the various capabilities of your camera. So go out there and play with your settings to see what actually works best for you.