Photography 1.10: How To Choose the Best Exposure

How do you know when you have chosen the best exposure settings for your photo? This is an important question and can confuse beginner photographers. Just as well that it’s not so difficult for me to answer. This article will help you understand how to choose the best exposure.

Have you ever taken some photos that have come out too dark or too light? You have underexposed them or overexposed them. This happens when not enough light or too much light reaches the camera’s sensor when you take a photo.

For photos to be well exposed the right amount of light must reach the camera’s sensor. Your camera has settings for controlling how much light the sensor receives. These can be set using various exposure modes.

When you have your camera set to any of the auto-exposure modes, this will not often be a problem. The camera will choose what it calculates is a good exposure. But will it always give you the best exposure? I do not believe that it will. Keep reading and I’ll explain why later in this article

I’ll take a brief look at exposure modes here, and will cover the main ones in separate articles because it’s important to understand them.

Most cameras have three main auto-exposure modes. These are:

• Aperture Priority
• Shutter Priority
• Program

With Aperture Priority and Shutter Priority you have some control.

In the Aperture Priority mode, you can control the aperture in your lens. This is an adjustable opening that can be opened up or closed down in stages called ‘stops’. The size of the opening is measured in f/stops. In this mode, the camera will calculate the required shutter speed.

Shutter Priority mode give you control of the shutter speed. This is the measurement of time the shutter is open for when you take a photo. Most often this is a fraction of a second. In this mode, the camera will calculate the required aperture setting.

With your camera set to Program mode, both the aperture and shutter speed will be calculated by the AI in your camera.

Manual mode is the most important exposure mode to understand and learn how to use. Many photographers are content to let the camera make exposure choices, I am not.

With your camera set to manual exposure mode, you must set the controls for both the aperture and shutter speed. This is not as complicated as it may seem and gives you more control over the way your photos look.

This allows you to be more creative because you have more control. You are not relying on the camera’s AI to make the exposure.

The best exposure can change from one photo to the next. Sometimes the changes are subtle, other times they must be extreme.

Our eyes don’t often have a problem with exposure. We generally see most things well. In severely bright or dark conditions we may not see clearly. If there’s a broad range of contrast between the lightest and darkest parts of a scene, we may struggle to see detail in every area.

When you walk outside from a dark room on a sunny day it takes a while for your eyes to adjust. Likewise, going into a dark room from a bright setting you will not be able to see clearly for a few seconds while your eyes adjust. This is very much like adjusting the aperture in a camera lens.

Cameras are more limited than our eyes when it comes to ‘seeing’ or recording images. They must receive the right amount of light to make a good exposure.

When there’s a lot of contrast in your composition, setting the exposure well becomes more of a challenge. Your camera will not be able to capture a good exposure of both the brightest and darkest parts of your picture.

In these circumstances you must choose what part of your composition you want to expose well. When your camera cannot evenly expose everything in your composition this is a very important choice to make. Your camera never knows what you are photographing or what your main subject is. This is why using manual mode is important, so you can make these choices yourself.

This is the basis of understanding what good exposure is and why your photos need to be well exposed.

Understanding that your eyes see different than your camera is an important first step in learning about exposure.

I know this may sound complicated, but stick with me in this series of articles, and I’ll explain it all as carefully as I can. It’s really not that complicated. Knowing how to set your exposure well allows you to be far more creative with your camera than if you let it make the creative choices for you.

Your camera is smart. It contains incredible software and AI. But it is not creative. You are!

Some technical purists will tell you each photo should contain a good range of detail. The darkest and the brightest areas of your composition should be well exposed. I do not teach this because I don’t believe that you can always make the best photos by sticking to that ideal.

I think it’s most important to have your main subject well exposed. This will not be true for some photos where you want to use your exposure settings to create a specific mood.

For now, I want you to concentrate on having your main subject well exposed - not too dark and not too light.

Lens - Standard

Exposure Mode - aperture priority

Focus Mode – Any

Location – Outdoors

Time – Any time of day

Find something to photograph with a bright background and something against a dark background. For this challenge set your camera to aperture priority mode.

With your subject in front of the bright background take some photos. If you can position yourself so the sky is behind your subject, do so. This will help by adding more contrast.

Make sure your subject is fairly small in your frame. It’s important that you can see a lot of the background in both sets of photos you make for this challenge.

Then take some more photos with your subject against a dark background. Try and find a place where your subject can be in the sun and the background is in the shade.

Take some notes about what you are doing and why.

Compare the two sets of photos. Are your exposures even? Is your subject well exposed in both sets of photos? What you see will depend on how much contrast there was in the scene you photographed.

In the photos against the dark background the contrast may not be so great. Your subject may still be fairly well exposed.

Modern cameras are a lot more forgiving when it comes to exposure. Sensors are continually being developed to manage good exposures over wider contrast ranges. This makes life as a photographer less challenging, but it’s still good to understand what makes a good exposure. I’ll continue to cover this subject in much more depth in other articles.