What Does The 'F' Button Do On FaceTime?

Apple released iOS 17 in 2023, bringing with it a bunch of new features, including personalized Contact Posters, an expandable Messages menu, and smarter autocorrect. Since then, Apple has continued to expand FaceTime's capabilities through subsequent iOS updates, with iOS 27 expected to have more features when it arrives in the fall of 2026. IOS 17 also introduced the "F" button to FaceTime calls on iPhones, but what this button actually does isn't immediately obvious from the icon.

During a FaceTime video call, you may have spotted a lowercase, stylized "F" button labeled "Portrait" at the bottom of the screen when you tap your own video preview. When you click the button, the background of your video becomes blurred while you remain in focus, similar to how you can blur the background of photos using Portrait mode in the iPhone Camera app. Below, we break down exactly what the "F" button does, how it works, and how to easily adjust the strength of the blur effect.

The "F" button available during FaceTime video calls enables Portrait mode, which creates a depth-of-field effect. It keeps people (or objects) in the foreground sharp while blurring the background, much like the background blur feature available during video calls in apps such as Google Meet.

The stylized "F" button is actually an f-stop icon. In photography, an f-stop (or f-number) measures how wide a camera lens' aperture opens and, therefore, how much light enters the camera. Lower f-stop numbers are best for portraits, as they let more light into the camera, making the background blurrier and the subject stand out, while higher numbers produce less blur. The FaceTime "F" button references this concept by applying a similar, albeit simulated, depth-of-field effect.

To enable Portrait mode, tap your video preview to expand it, then select the Portrait/"F" button from the menu at the bottom of the screen (it should be next to the Studio Light button). Once enabled, Portrait mode blurs your background while keeping you in focus. This feature is particularly useful if you want to draw attention to yourself rather than your surroundings. It can also help hide a cluttered room or add an extra layer of privacy by making your background less visible during a call.

On a traditional camera, adjusting the aperture changes the depth of field and, in turn, the amount of background blur. While Apple doesn't let you manually adjust a virtual aperture, you can adjust the intensity of FaceTime's background blur.

To do so, start a FaceTime call and enable Portrait mode. Then, swipe down from the top-right corner of the screen to open Control Center. Tap the FaceTime Controls" button at the top of your screen to access FaceTime's audio and video settings, then select Portrait from the video beside your live video preview.

This opens a depth slider that lets you adjust the strength of background blur while previewing the adjustments in real time. Moving the slider to the right increases the blur effect, while moving it to the left makes the background appear sharper. Set the slider as you see fit, then exit the Control Center and continue your call.