If you read this post, you will learn everything you need to know about the apertures. Along with the ISO value and the exposure time, it is one of the three most important camera settings in photography. Especially as a photography beginner it is extremely important that you understand the function of the aperture and learn from the beginning how you can create your pictures with it. I will help you get the most out of your camera!

How’s the Aperture?

The aperture mainly influences two aspects of an image. It adds dimension to your photos by blurring the background and it changes the exposure by darkening or brightening shots. The following two images are exactly identical except for the background, which is once sharp and once out of focus. You can control this blur (also called depth of field) with the aperture by adjusting this at your camera.

How does the Aperture work?

Loosely speaking, the aperture is a hole in your lens through which light falls into the body of the camera. It works like an eye: your pupils get bigger or smaller depending on how much light is available. Transferred to photography this means: the aperture is the pupil of your lens. It can also be enlarged or reduced at will. This controls how much light falls on the camera sensor. The interlocking “wings” or ” blades” form a kind of barrier to block light. So the only way in is through the hole in the middle. The technical definition for the aperture is: “The opening in a lens through which light passes into the interior of the camera.

Influence of the aperture on the exposure

The aperture can have several effects on your images. The most important one is brightness, also called exposure. If you make the aperture larger (more open), more light comes in and your image becomes brighter. If it is smaller, the image automatically becomes darker. In a dark environment you should therefore use a wide open aperture to capture as much light as possible. That makes sense, because for the same reason your pupils get bigger at night.

Depth of field: Sharpness of the background

The sharpness or blur of the background is called depth of field and is also controlled by the aperture. It indicates from wich point to which area in depth your image is sharp. Some images have a “flat” depth of field, which leads to a blurred background. Others have a high depth of field, with the sharpness running through the photo from beginning to end. Read our article about depth of field here. You’ re gonna learn how to do great effects with it.

In the picture below, only the front bottle is sharp, which is due to the carefully chosen, wide open aperture. Here you can see the Shallow-Focus-Effect, which I have chosen intentionally because it gives the image a nice shallow depth of field. If I had made the aperture smaller all the bottles would be sharp from front to back.

To remember the principle, remember this: A large aperture causes great blurriness in the depths. This effect is very popular for portraits, by the way, as well as for photos of objects where you want a blurred background. The photo above has a blurred background and a very pleasant bokeh, which makes it special. Conversely, a small aperture produces less blur. This is ideal forlandscape photography or architectural images, for example, where the foreground and background usually need to be sharp.

If an image is to be sharp throughout and an object is in the foreground (such as a stone), then other rules apply again. If you are especially interested in landscape photography, I recommend that you read all about hyperfocal distance after this article.

What does the F Number or F Stop mean?

So far we have only used the terms ” small ” and ” large ” to describe the aperture. But the size of the aperture can also be given in numbers. This number is called the F-number or F-stop. In front of each aperture value is the letter “f” – for example f/8. You’ve probably seen it before on your camera; maybe on the display or in the viewfinder. Some models do without the slash, these numbers then look like this: f2, f3.5, f8 etc.

Large vs. Small Aperture

What always confuses beginners is the fact that a small f-stop number stands for a large aperture and a large f-stop number for a small aperture. Aperture f/4 is therefore larger (more open) than f/8 and much larger than f/13. Most people find this funny, because it should be the other way around. But this is not a spelling mistake: The aperture is a fraction or respectively a fraction. You’re thinking uh-oh, is he really gonna do the math for me? Yeah, but trust me, it makes it so much easier. A value of f/10 stands for a tenth. If you paid a little attention in school, you know that a tenth is clearly smaller than a quarter. And exactly for this reason f/10 is smaller than f/4.

Therefore, if someone advises you to use a large aperture for a particular photo, then f/1.4, f/2, f/2.8 or similar is meant. If you are advised to use a small aperture, use f/8, f/11 or f/16.

Choosing the right aperture

Now you know what the different aperture values mean. But which one do you use when? Here is a small graph that shows the difference in brightness between some common aperture stops:

In a darker environment you should use large apertures such as f/2.8 to make the photo bright enough. As already explained, the pupils of your eyes also open in the dark to capture even the smallest bit of light.

Regarding the depth of field, we would like to remind you that an open aperture like f/2.8 leads to too much blur in the background. That would be great for portraits. Aperture settings such as f/8, f/11 or f/16, on the other hand, help you to get a sharp picture from front to back. This is good for landscape photos.

Don’t be upset if your photo is too bright or too dark with the aperture set. You can usually correct with the exposure time or ISO when the aperture reaches its limit.

Aperture values and their influence

For repetition; here again everything you have learned so far:

Setting the aperture correctly

If you want to set your aperture manually (which we highly recommend), there are two camera modes available. One is aperture priority mode and the other is manual mode. The former is marked with “A” or “Av” on most cameras, the latter with a simple “M”. You can find these letters on the mode dial of the camera.

In aperture priority mode you set the aperture yourself and the camera takes care of the exposure time. In manual you can control everything yourself.

Maximum and Minimum Aperture of Lenses

Each lens has a limit on how large or small the aperture can be. You can find this information in the technical data of your lens. Most important is actually the maximum size. It tells you how much light the lens can receive and whether you can take “good” photos in the dark. A maximum aperture of f/1.4 or f/1.8 indicates a very “fast” lens because more light passes through it. The term “slow” is then e.g. f/4. Fast lenses usually cost a lot more than “slow” ones.

The minimum aperture on the other hand is not that important, because most modern lenses go up to f/16 or lower anyway. You will rarely need a smaller aperture in everyday life.

With some zoom lenses, the aperture may change when you zoom in or out. With the Nikon 18-55mm f/3.5-5.6 for example, the largest aperture is f/3.5. But if you zoom in closer, it will automatically shrink. More expensive lenses, such as the Nikon 24-70mm f/2.8, can maintain the aperture even when zooming. But the largest fixed apertures often have lenses with fixed focal length (e.g. 50mm), so they have an advantage over zoom lenses.

The maximum aperture of a lens is so important that the value is even mentioned in the name, resp. of the product name. This is then often written with a colon instead of a slash – but the meaning is the same. The smallest aperture, respectively the “open aperture” theoretically has a value of f1. In practice, however, this is hardly physically possible due to the design of the cameras and lenses.

Zooming and f-stops

When you zoom, you change the focal length. The zoom setting affects the possible aperture values that can be set on the camera. If a subject is “brought closer” with an optical zoom, the lowest aperture stops are maby no longer adjustable. At low zoom, the minimum value is e.g. f/2.8 depending on the lens, at active zoom it is e.g. f5.6. So your camera is not broken if you can’t adjust the values anymore – but with active zoom the aperture has to be closed increasingly. The same principle applies here again. When you look into the distance, you squint your eyes.

Controlling brightness with aperture or shutter speed

As already briefly mentioned, the exposure / shutter time is very closely related to the aperture. It indicates how many seconds light falls through the lens onto the sensor. With a large aperture (small light transmission), the exposure time or shutter speedmust be correspondingly longer so that the same amount of light falls on the sensor as with a small aperture (large light transmission). The following diagram shows you the connections:

For longer exposures, a tripod may need to be used. A rule of thumb says that a tripod should be used from approx. 1/15 second exposure time on to avoid shaking the image. The image can quickly become too dark if you only select a larger aperture and do not adjust the exposure time. The brightness of the image is therefore not affected purely by the setting of the aperture, but only by the exposure time. In our example with the “AV” mode, the exposure time is determined automatically by the camera. If you switch to the “M” mode, every setting can be adjusted manually, including the exposure time.

Practical examples of different apertures

Now that we’ve gone through a thorough explanation of how the aperture works and how it affects your images, let’s take a look at examples at different aperture settings.

Summary Aperture

The aperture is an essential setting in photography, if not the most important of all. It has an effect on both depth of field and exposure. There are actually no more important elements for a photo.