Choosing the aperture setting is all about whether you want the photo to be sharp in every detail, or whether you need to separate the subject from the background. Setting the aperture to a small aperture number will give you a shallow depth of field. Setting the aperture to a high aperture number will then take photos that are sharp throughout the entire depth of field of the image.

What is aperture and what is aperture number

The aperture is the hole in the lens through which light hits the camera chip. The size of the aperture is indicated by the numerical value of the aperture number f usually from 1.2 to 32. Lower values mean a larger aperture diameter. Higher aperture values, on the other hand, indicate a small aperture diameter.

How to set the aperture

View through the open aperture in the camera body

The two extreme values of the aperture setting f are determined by the optical design of the lens. Therefore, for example, the lowest possible aperture number setting for a lens with an f/2.8 aperture is f/2.8. The aperture is indicated by numerical values of one exposure step of 1EV, usually in the range 1; 1.4; 2; 2.8; 4; 5.6; 8; 11; 16; 22.

Illustrative representation of aperture blade opening for different aperture number sizes

What the aperture is used for Aperture number depth of field

The smaller the f-value, the larger the aperture and the greater the intensity of light hitting the camera chip. We have set a large aperture for the lens. This results in a blurrier background and a brighter photo. By adjusting the aperture, you therefore control the depth of field of the photograph, i.e. the range of focus distance from the subject in focus. Changing the aperture size is accomplished by mechanically adjusting the aperture blades inside the lens. By adjusting from one aperture value to the next, adjacent f value, we double or halve the intensity of light passing through the lens onto the camera chip. The intensity of light means the lens luminosity. The maximum light intensity of a lens is determined by its optical design. The minimum luminosity is determined by the possibility of setting a large aperture number.

Photographs with a shallow depth of field. Birds perched on the railing further back are also more blurred due to the small aperture setting. With a larger aperture setting, the photo will be sharp throughout, and birds sitting in the back will also be sharply rendered. The aperture setting value f is shown in the viewfinder or on the display after the letter f. Turn the wheel to increase or decrease the aperture value. But it all depends on the type of camera and the mode you have the camera set to. In automatic mode, you usually cannot change the aperture setting. It’s best to switch the camera to Aperture Priority A or Av mode.

The back of the SLR with the display and controls

Tip for shooting running water. Set the aperture to f/22 and the ISO to 100. This allows you to set a longer exposure time. This setting will blur the flowing water into a rolling mist while everything around you is in focus.

Aperture Depth of Field – What is the correct aperture number

Using a large aperture number makes your photos sharper throughout, but then you have to use a longer shutter speed. Setting a higher aperture number (f/11) will find use when photographing groups or when you want to take a background shot of, say, your favourite castle. A small aperture number is useful when taking portraits or macro photography. Your photos will have a shallow depth of field. Remember, by setting a small aperture number, you can separate the subject from the background as well as the foreground. Setting the aperture value f therefore allows you to control the so-called depth of field. By setting the f-value higher, you are telling the camera that you want everything in the background of the photo to be sharply rendered as well. The higher you set the aperture value, the sharper the rendering will be. Remember aperture depth of field.

How to set the aperture for portrait photography – minimum aperture mode

Distance from photographed object in meters

Let’s try it out. Our young photographer wants to take a picture of a calf. She sets the aperture number to two. She wants to get a nice photo, so she kneels down so that her camera is at eye level with the calf. She also focuses on the calf’s eyes. Since her aperture number is set low, everything in front of and behind the calf will be out of focus. The blur will be greater the further the subjects in the photo are from the line of focus. In this case, it’s the calf’s eyes.

How to set the aperture for nature photography

Distance from photographed object in meters

The background does appear very blurry to the photographer. So she changes the camera settings and sets the aperture to f/5.6, which is suitable for nature photography. She uses the same procedure to take the photo. As we can see in the orange arrow, the depth of field has changed. The photo is now sharp at a greater depth of field. In our case, about four meters, which is enough to bring the girl behind the calf into focus as well. Even the spruce tree in the background is no longer so blurry.

How to set the aperture for landscape photography

Distance from photographed object in meters

Since the surrounding landscape is also interesting, the girl decides to take a photo that is sharp throughout. So she sets the aperture number to f/11, which is suitable for landscape photography. This ensures that the calf, the girl and the spruce tree in the background are in focus. This setting will show everything in sharp focus. In this case, from the point of view of the composition of the photo, it is also important to observe the light and the space itself. Otherwise, you may end up with a nice colour shot of everything, but it will be boring.

Tip on how to set the aperture for shooting in backlight

Shooting in backlight offers many creative possibilities, such as shooting silhouettes. The best time to shoot silhouettes is golden hour, the time before sunset or after sunrise.

What aperture to set when shooting in backlight

A suitable aperture setting for shooting in backlight is f16 or larger. This aperture setting will render the rays of light coming from the sun. Due to the very high aperture and short shutter speed, you may need to increase the ISO to 400. For 22 more photography tips, check out 22x Tips on how to take photos, set up your camera and get started shooting properly

How to set the aperture – photo examples for portrait, group, nature and landscape photography

You can see how aperture settings work in real photographs with the following examples, for different aperture settings. f

Set this aperture value when shooting two people or when shooting indoors or in the garden
It also always depends on the amount of light and the speed of movement of the subject. If there is less light, increase the exposure time, When shooting motion, decrease the exposure time and increase the ISO.
How do I use the aperture to separate the subject from the background to create a soft and smooth bokeh?

Stand close to the subject and set the aperture number on the lens as small as possible. Some lenses can blur the background much more and better than others. If you don’t like your bokeh, consider buying a good portrait lens, For Nikon cameras, I recommend the Nikon 50mm f/1.4. The Nikon 85mm f/1.4 is considered one of the best lenses when it comes to bokeh.

Useful apps for cameras on mobile

Depth of field calculatorDOF calculator allows you to calculate the exact depth of field. Knowing your exact depth of field is useful for macro photography, product photography or portrait photography.
photo exposure calculator
Use the Exposure Calculator app to quickly calculate individual exposure parameters.
Frequently asked questions for aperture settings

Can I use the aperture to affect the background blur of a photo? Yes, the background blur of the photo is controlled by the aperture setting. As a rule of thumb, the smaller the aperture number, the blurrier the background of the photo. What aperture should I use when shooting groups? When shooting groups, we usually need to achieve a greater depth of field. This is achieved by setting a larger aperture – usually greater than f5.6. If you’re shooting multiple people, set the aperture number to f11. How do I set the aperture when shooting landscapes? If you’re not doing creative photography, you’re better off choosing a larger aperture number of f11. The photo will then be sharper throughout.
It will still get complicated, practical experience is worth a thousand words – visit my photography course. We’ll discuss everything practically, and if a photo goes wrong never mind, we’ll talk about how to do it.