fStop
The physical camera aperture simulated by SceneKit for depth-of-field effects. Animatable.
Declaration
var fStop: CGFloat { get set }Discussion
F-stop numbers describe the light-gathering area of a physical camera’s imaging system, and are typically expressed as the denominator of a ratio including the camera’s focal length ƒ, such as ƒ/2 or ƒ/5.6. A larger denominator indicates a smaller aperture, allowing less light to pass from the camera’s lens through to the imaging plane (sensor or film), and a smaller denominator indicates a larger aperture that lets more light through.
SceneKit uses aperture measurements to simulate depth-of-field blur effects (also called bokeh) approximating those produced by a physical camera. A larger fStop number (or aperture denominator) causes most of the scene to appear in focus, with extremely close or far depths showing slight blurring; a smaller number results in only a narrow range of depths appearing in focus, and a more pronounced blur effect for the rest of the scene. The default fStop value is 5.6.
You can animate changes to this property’s value. See Animating SceneKit Content.