Knowing when to use a narrow aperture or wide aperture can make the difference between a good and a bad picture. In our article, you learn about arguably the most important setting on your camera, the aperture. So, open your mind, and we’ll shed some light on the subject!
What Is a Wide Aperture?
The aperture is the hole in the lens that lets light through. This hole can be made larger or smaller. It’s like a faucet that controls how much water comes through, depending on how wide you open it. A wide aperture lets more light enter.
Here are some other details you should know about your lens and aperture:
- Diaphragm Ring: The aperture is controlled by a ring within your lens. Every conventional lens has this ring. (Catadioptric or “mirror” telephoto lenses have a fixed aperture.)
- F-Number: The f-number describes how large the aperture is. Larger numbers mean a smaller opening (narrow aperture). Smaller numbers mean larger openings (wide aperture). A large aperture is f/1.8, while f/22 is considered small.
- Lenses: Prime lenses always have the widest apertures. They can be as large as f/0.85! The largest aperture available on zoom lenses is f/2.8.
- Exposure Value: Aperture is one of three settings that controls exposure value. For any given amount of light, there is an exposure value. You combine the three elements of exposure to provide the right amount of light for your photo. Aperture is one element. The other settings are ISO and shutter speed.
Why Is It Important to Know How to Use a Wide Aperture?
A wide aperture does more than change how much light reaches your sensor or film. Understanding the effects of aperture is essential for getting the most out of your photography.
It’s important to note that, for this discussion, an aperture of f/2.8 is considered a wide aperture (large). You need this aperture setting or even larger to achieve some of the effects we discuss.
Depth of Field With Wide Apertures
When you focus your camera, you, of course, choose a subject to focus on. This, for example, could be a person in a portrait photo. One main effect of your aperture is how much is focused in front and behind the focal point.
A wide aperture produces a shallow depth of field. This makes only the main subject sharp. And the area in front and behind the subject is out of focus. This means a large aperture is perfect for isolating your subject using focus. It provides less distraction from the main subject of the photo.
If the main subject is sharp, there can be a large part of the photo that isn’t. This area is often referred to by photographers as bokeh. Wide apertures help create this bokeh effect.
But not all lenses create bokeh equally. This is why reviews often mention the quality of bokeh produced by a lens. The best examples paint a smooth, creamy background that doesn’t distract.
It’s possible to do even more with bokeh. You can create shaped bokeh like hearts, stars, or electric bolts. You cut a black circle from some paper to do this. You then cut the shape you desire into the black circle and ensure it is in the center of your black paper disc. Place it over your lens and shoot away!
A lens with a wide maximum aperture is called “fast.” Because it lets in a good amount of light quickly, a good fast lens is a must-have for low-light photography. But modern cameras perform extraordinary things with high ISOs. And this makes a fast lens less important.
Ting said, you’ll often struggle for light without a large aperture, especially when it comes to night street photography. Get a good quality 50mm lens with a wide aperture, and you’ll be set for most street photography camera settings.
Action photography often means sports photography, which makes using a wide aperture tricky. That’s due to the shallow depth of field and because the main subject is moving. You will often need to be moving the camera as well.
Even with modern autofocus (AF) systems, this can make it difficult to get the focus right. But your image looks amazing when you get the focus right with a large aperture.
Get to know your camera’s focus-tracking function. It helps you keep your subject focused.
The Importance of Narrow Apertures
At the other end of the scale is a narrow aperture. This means an aperture of f/16 or smaller. It should be noted that you wouldn’t normally use an aperture this small for landscape photos.
Depending on the lens, the sharpest focus is usually achieved at f/8 or f/11. The following are ways in which narrow apertures can benefit your photography.
Depth of Field With a Narrow Aperture
If you want elements in the foreground and background of your photo to be in focus, you need to use a narrow aperture. All other things being equal, wide-angle lenses have a greater depth of field than telephotos.
The effect of this narrow aperture is a large depth of field, with most areas of the photo being in focus. For example, if you have a line of people and want them to all be in focus, you need to use a large depth of field.
As mentioned, most landscape photos should be photographed at that lens’s sweet spot aperture, often f/8.
With a narrower (smaller) aperture than that, there is usually a drop-off in sharpness. This is due to lens construction. But if there are strong foreground elements that you want to be in focus, then a narrower aperture is needed.
Focusing on an object very close to the camera, even using a small aperture, might not be enough to keep the background sharp. In that case, bracketing your images for focus is an option.
Focus-stacked images can then correct focus problems in post-processing. Some modern cameras will even handle the focus stacking for you!
A starburst effect (sun stars) can only be achieved using a narrow aperture. It causes a point of light to have spikes.
The type of diaphragm your lens has will affect the number of spikes produced. If the diaphragm has an even number of blades, then the number of blades equals the number of starburst spikes produced.
If the number of blades is uneven, you get double the number of spikes. This means that 9 blades will produce a starburst with 18 spikes. It should be noted there is a starburst filter you can use to create spikes. But it looks better and more natural using a small aperture.
It’s possible to produce the starburst effect from street lights and even sunlight. Follow these instructions to be successful with these shots:
- Street lights: You need a tripod since narrow apertures and street lights mean a long exposure at night. Experiment with the aperture a little. The smaller the aperture, the longer and thinner the spikes will be.
- Sunlight: Photographing the whole sun won’t produce a good starburst effect. The sun will likely overexpose your photo if you’re aiming at it. It’s also not good for your eyes unless the sun is nearing sunset. So, finding ways of reducing the amount of sun photographed is best. In other words, find a way of blocking the sun. This could be done by using leaves on a tree, clouds as they pass in the sky, or the horizon line as the sun begins to set.
Narrow Apertures and Slow Shutter Speeds
The laws of physics mean you must adjust your ISO or shutter speed to use a small aperture. A small aperture, especially when you shoot into the evening, results in slow shutter speeds.
Other effects that you can get from slow shutter speed are the flattening of water or making white water appear like silk. These photos, often taken during the day, need a small aperture. This is to get long exposures between 1 and 20 seconds to achieve the effect. (You might also need an ND filter.)
A smaller aperture is useful when panning to follow a moving object. The increased depth of field makes it easier to achieve a sharper focus on the object you’re panning.
Conclusion: Wide vs Narrow Aperture
Learning about using a wide aperture vs a narrow aperture is important for your photography. It’s a setting with a great deal of creative potential. You need to know about its relationship with shutter speed as well.
A lot of photographers use Aperture Priority mode for many of their photos. It speeds up changing your settings, and aperture is that important.
How do you use aperture in your photography? Do you use aperture priority, or do you go fully manual? We’d love to see example photos that have used aperture for creative effects.
Please leave your thoughts and photos in the comments section of this article. And check out our post on when to shoot portrait vs landscape next!