What Does F/1.8 Mean on a Lens?

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Photography is made up of three major pillars: shutter speed, ISO and aperture. Aperture plays a key role in determining how much light is let in, along with how much depth of field is in each photo. If you’re new to photography, you might hear people use terms such as f-stop when referring to the aperture.

There’s a range of f-stops, and a common one for prime lenses is f/1.8. So, what does f/1.8 mean on a lens?

What Does F/1.8 Mean on a Lens?

F/1.8 means that the aperture is wide open and you will have a shallow depth of field. This means that more light will be let into the camera compared to narrower f-stops like f/4, f/11, or f/16.

Having a lens with a wide aperture like f/1.8 allows you to take photos in low light conditions without always needing to increase your ISO or use a tripod and external camera flash.

F/1.8 camera lens

What Do You Need to Know About Aperture and F-Stops?

Before you buy a lens, you need to ensure you know its capabilities when it comes to the aperture range. F-stops refer to the description of the aperture size for any lens. Small numbers (like f/1.8) denote wider apertures while larger numbers (like f/22) denote smaller apertures.

F-stops are determined by dividing the focal length of the lens and diameter of the aperture of the lens. However, they are usually marked on the camera or on the length of the lens you are using.

A small aperture is ideal for landscapes and architecture as it results in very little foreground and background blur. A wide aperture is better for portraits as it provides great background and foreground blur.

Thus, with a lens adjusted to f/1.8, you are likely to produce the best pictures in a low lighting scenario. If you’ve adjusted your aperture to f/1.8 you might not even need a camera flash. You will also get a shallow depth of field, enabling you to isolate the subject from the background and foreground to get a sharper image.

In scenarios where there is a lot of light, you may need to lower your ISO settings and increase shutter speed settings when using f/1.8. This is because at f/1.8, your aperture is wide open and already letting in a lot of light.

How Does a F/1.8 Aperture Affect Your Photos?

When shooting with a prime lens that opens up to f/1.8, it’s important to know how this setting affects the outcome of your images.

Increased Shutter Speed

When you can shoot with your f-stop at 1.8, it allows you to keep your shutter speed at a higher rate, especially in dimly lit situations. This can be really useful when shooting wedding ceremonies in dark churches where you are not allowed to use a flash.

Nikon camera lens

Shallower Depth of Field

A good lens can help you capture a fantastic picture, but the size of aperture will determine how much of the subject is in focus. With a wide aperture of f/1.8, you have the option to isolate the subject from the rest of the image.

This means that you can focus on one main thing within your frame and blur out the background for a beautiful effect. Focusing on a subject will allow you to capture finer details, color, and even raw emotion in portraits.

Bright and Creamy Images

You can take bright images with a range of f-stops; however, you get a bright and creamy image when you set your aperture to 1.8. Shallow apertures work great for portraiture, because it naturally smooths out skin tones.

For example, if you’re taking a portrait of a woman and you focus on her eyes, they will be very sharp. But, because you’re at f/1.8, the rest of her face will appear softer because of the shallow depth of field.

Frequently Asked Questions

Is F/1.8 or F/2.2 Aperture Better?

If you are wanting a shallower depth of field, then f/1.8 is better than f/2.2. The lower the f-stop value, the more light that can hit your camera sensor. An aperture of 1.8 will give better results under lower lighting situations.


Understanding what f-stops are and how apertures plays a role in the outcome of a photo will help you not only in buying the right lens but also in improving your photography skills. By understanding how they both relate to photography, you will be able to dial in your camera settings and take better photos.

Kaitlin Cooper is an active professional wedding and portrait photographer in San Diego, California at Kaitlin Cooper Photography. She is also a contributor to many large publications, including Bridal GuideBustlePixpaWith Joy, and Hello Giggles.