What Role Does Exposure Play In Photography?

By Faisal Al Islam

The exposure of a photograph provides a general indication of how light or dark the photo is. We say that a picture has underexposure when it is too dark and overexposure when it is too bright. To achieve the desired exposure, we adjust the settings on our camera. This is accomplished by adjusting a few important settings, including the aperture, shutter speed, and ISO. These three settings are known together as the 'exposure triangle.' To achieve the desired exposure, you must strike a balance between the various settings in the exposure triangle and have a solid understanding of how light behaves.

Apart from shutter speed and ISO, an aperture is the first component of the exposure triangle as well as the initial component of a camera. It determines how much light enters your camera and how much light is captured. Enhancing the size of your aperture will cause your image to appear brighter but decreasing it would cause it to appear darker. Think about what happens to your eyes when there is darkness? Your pupil expands to allow more light into your eyes to see things better. And your pupil contracts to let in less light to see better when you are out in the hot sun. Different aperture sizes can produce perfectly exposed images depending on the circumstances.

How can we adjust the aperture to capture a good image? It is also sometimes referred to as f-stop or f-number, a technique for measuring the size of the aperture in each lens. This f-stop scale goes from F1 to F1.4 to F2 to F2.8, to F4 and beyond. However, there are two aspects of this f-stop scale that have the potential to cause confusion. First, a smaller F number corresponds to a greater aperture, and a higher F-number corresponds to a narrower aperture. So, if we take F 2.8, it is essentially a bigger aperture and allows in more light than an F11. Another perplexing aspect is the fact that not all lenses are created equal. Because of the high-cost engineering, it is challenging to produce broad apertures such as F1.4 or F2.

Aperture also affects other things like depth of field. A shallow depth of field is achieved by using a wide-open aperture, which means that only a tiny portion of the scene is in sharp focus. A smaller aperture has a deeper depth of field. Shooting a wide-open landscape and wanting everything in focus, you have to close down your aperture, making it smaller. If you are shooting a portrait and you want a blurry background, open up your aperture, and make it wider.

And just a reminder if you are opening up your aperture, you are actually making your f-stop number smaller, if you are closing down your aperture, you are making your f-stop number bigger. This shallow depth of field is one of the things that can make a not-so-great photo look more professional. But remember not all cameras and not all lenses can open up to very wide apertures. Therefore, depending on your equipment, this may or may not be possible.

In a nutshell, we already understand what aperture is and how it affects exposure. Aside from that, you need more practice adjusting aperture settings to see how different settings affect the exposure and the depth of field.

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