Photo Booth consists of a single window containing a viewer that provides a preview when taking photo snapshots or video clips. Thumbnails of saved photos and videos are displayed along the bottom of the window. These can be shown or played by double clicking on the thumbnails.
Clicking the large red button underneath the preview area starts a 3-second countdown, after which a photo is snapped or a video clip begins recording, depending on which setting is selected. Effects can be applied by clicking on the "Effects" button. In addition, users can apply backdrops to provide an effect similar to a green screen. When a backdrop is selected, a message appears telling the user to step away from the camera. Once the background is analyzed, the user steps back in front of the camera and is shown in front of the chosen backdrop.
Photo Booth has two sets of image effects that can be applied when taking a picture. The first set contains photographic filters similar to those in Adobe Photoshop, and additional effects may be downloaded from websites.
In the latest version of Photo Booth included with Mac OS X v10.5 Leopard, the application incorporates the Chroma key technology which is used in professional film making to replace the background of a frame with an image or a video clip. Photo Booth incorporates this technology by recognizing a still background, then replacing it with either a pre-set image or movie clip, or allowing the user to choose their own background.
Backgrounds are available only on Macs featuring an Intel processor. By default, Photo Booth's live preview and captured images are reversed horizontally, to simulate the user looking into a mirror; however, it can flip the image automatically or upon request to provide a true-to-life representation.