What is aperture? (With definition and benefits of use)

Updated 7 June 2023

If you're hoping to build a career in photography, you may aspire to achieve greater control over your camera. To be a professional photographer, abandoning auto modes in favour of manual options such as aperture can be beneficial. By manually manipulating all three exposure triangle parameters, you're able to bring out a finer quality in your photos. In this article, we answer the question, 'What is aperture?' and discuss some examples of aperture use and everything aperture does to your photos.

What is aperture?

Aperture refers to the opening of a lens by which light flows to reach the camera. If you consider how your eyes function, it's a similar concept. The iris in your eyes grows or contracts when you walk between dark and bright settings, affecting the diameter of the pupil. Aperture refers to the pupil of the lens in photographing. To enable more or less light to penetrate the image sensor, you're able to reduce or increase the aperture size.

Although most lenses include a variety of apertures, they're commonly referred to by their greatest or biggest aperture, such as '85mm f/1.8'. Many zoom lenses include a 'moving' aperture, which means the maximum aperture adjusts when the lens zooms in and out. An f/3.5-5.6 lens, for example, seems to have a maximum aperture of f/3.5 at the widest part but reduces to f/5.6 when zoomed to the telephoto side.

The importance of aperture in photography

One of the most common mistakes wildlife photographers make is ignoring the many advantages that come with photographing at a range of aperture settings. A collection of moving blades in a lens regulates the size of the hole by which light flows to the sensor, creating the aperture.

Managing the size of the hole in the lens remains important for getting proper exposure, but it also gives you the freedom to experiment with clarity and blur. A wide aperture, such as f/2.8, blurs more of the picture, but a higher f-number takes more of the area into fine focus.

How does aperture relate to exposure?

Aperture puts a variety of effects on your photos. The brilliance or exposition of your photos makes up one of the most critical factors. The quantity of light reaching the camera sensor varies as the aperture changes in size. The quality of the image varies accordingly.

A big aperture allows more light to pass through, leading to a brighter image. A narrow aperture has the opposite effect, darkening a photograph. Choose a big aperture in a gloomy location, such as inside or at night, to collect as much daylight as possible. When it becomes dark, your pupils dilate for about the same reason.

How does aperture affect depth of field?

Depth of field refers to the area of your picture that appears precise from the front to the back. The backdrop in some photographs has a narrow depth of field, meaning it's entirely out of focus. Other photographs have a deep depth of field, with a distinct foreground.

A big aperture produces excess blur in the foreground, which remains useful for general photographs of things when the subject requires isolation. Frame your topic using foreground items that appear blurry compared to the subject. A smaller aperture produces a modest background blur, which is good for particular genres of photography, such as architecture.

What's the difference between the f-number and the f-stop?

You measure aperture in 'f-numbers' or 'f-stops', with the letter 'f' coming before the number, such as f/8. Your aperture's found on your LCD panel or viewfinder as f/2, f/8 and so on. Some cameras remove the slash and instead write the f-stops as f2, f8 and so on.

When do photographers use aperture settings?

You may use apertures of roughly f/8 to f/14 for nature photography and when incorporating wide-angle lenses. This is because of a well-performing lens near that aperture. Photographers use apertures by:

Photographing at night

When taking photographs in the evening or at night when the light is dim, a narrower aperture frequently requires a longer shutter speed to achieve a properly illuminated image. This isn't a huge thing if you're working from a tripod, unless you're shooting incredibly long shutter speeds, like 10 minutes. Photographers utilise a little faster aperture during the night. To achieve a properly exposed photograph with no unsharp movement, you need a fast aperture and a higher ISO.

Enhancing foreground blur

A wide aperture produces a hazy out-of-focus background in your photograph. When coming very near to an object, such as flowers, apply this in the foreground. Generate a blurred and out-of-focus foreground by utilising a wide aperture, leading viewers into the distance. People utilise a wide aperture to generate a more hazy foreground for this reason.

Incorporating sunstars

When the sun comes close to an edge, such as the horizon, it appears like a star in an image. You can determine the impact of a sunstar by the lens' features and the arrangement of the aperture blades. Some lenses feature wonderful sunstars. Kit lenses frequently feature sunstars that seem generic. Use a narrow aperture of roughly f/14 to f/22 to capture a sunstar. Close your lens a lot to achieve the best result. The patterns of the blades affect how the light comes through them when you close your lens, presenting the sunstar in your picture.

Benefits of a wide aperture

Though some of the industry's most talented photographers like to shoot with a fully open aperture, others may not work with anything less than an f/4.0. This may be because of preference or other factors, such as the requirements of a photography project. Benefits of a large aperture include:

Works with a difficult location

You won't always have the choice of using an ideal setting depending on the sort of photography you shoot. For example, perhaps the venue of a shoot that was put in a schedule months ago changed after your arrival. Or perhaps you just want to get a certain shot done quickly and can't find a new location.

Whatever the source of your problems, a wide-open aperture can help. With such a small depth of focus, anything concerning you about the backdrop quickly fades into a lovely bokeh. Using an f-stop of f/2.0 or below allows you to work in less-than-ideal conditions since the incredibly narrow depth of field enables you to hide imperfections.

Produces detailed shots

A short depth of focus provides some stunning detail photos. If you look at current photography trends, you may notice that several industry leaders use wide-open apertures to capture flowers, jewellery and centrepieces. This is because images taken with a big aperture concentrate all the emphasis on the subject, and the surrounding fades away. A narrow depth of field remains ideal for occasions like weddings when the arrangements might seem crowded if you just want to focus on one small component of the set-up. Wide apertures remain popular in music photography for about the same reason.

Post-processing is less necessary

With all the photograph editing technologies available, practically anything seems possible if you have the proper understanding. Editing an image can be time-intensive, making adjusting your camera settings to achieve the desired shot often more beneficial than editing an image.

Filmmakers frequently use wide-open apertures to achieve a softer focus and shallow depth of field, giving the audience the impression of being in a dream state. This is to mimic dreaming, as when you wake up, it's frequently difficult to recall certain of your dreams precisely and sharply. As a result, pictures that remain soft and slightly out of focus have an association with dreams.

Low-light photography becomes easier

If natural light is at a premium, achieving the proper exposure may be difficult. You may need a lens with a large enough aperture to let in additional light if you want to shoot a well-exposed picture in low light. Using a lens with an f/1.8 aperture, for instance, is a useful method to let sufficient light in and brighten the picture.

Remember that the aperture refers to the opening in your lens through which light flows. More light enters the lens when the aperture's opened wider. Learning how to coordinate the aperture with either the natural or low light conditions is key to an outstanding final product.