constructor( fov = 50, aspect = 1, near = 0.1, far = 2000 ) {

		super();

		/**
		 * This flag can be used for type testing.
		 *
		 * @type {boolean}
		 * @readonly
		 * @default true
		 */
		this.isPerspectiveCamera = true;

		this.type = 'PerspectiveCamera';

		/**
		 * The vertical field of view, from bottom to top of view,
		 * in degrees.
		 *
		 * @type {number}
		 * @default 50
		 */
		this.fov = fov;

		/**
		 * The zoom factor of the camera.
		 *
		 * @type {number}
		 * @default 1
		 */
		this.zoom = 1;

		/**
		 * The camera's near plane. The valid range is greater than `0`
		 * and less than the current value of {@link PerspectiveCamera#far}.
		 *
		 * Note that, unlike for the {@link OrthographicCamera}, `0` is <em>not</em> a
		 * valid value for a perspective camera's near plane.
		 *
		 * @type {number}
		 * @default 0.1
		 */
		this.near = near;

		/**
		 * The camera's far plane. Must be greater than the
		 * current value of {@link PerspectiveCamera#near}.
		 *
		 * @type {number}
		 * @default 2000
		 */
		this.far = far;

		/**
		 * Object distance used for stereoscopy and depth-of-field effects. This
		 * parameter does not influence the projection matrix unless a
		 * {@link StereoCamera} is being used.
		 *
		 * @type {number}
		 * @default 10
		 */
		this.focus = 10;

		/**
		 * The aspect ratio, usually the canvas width / canvas height.
		 *
		 * @type {number}
		 * @default 1
		 */
		this.aspect = aspect;

		/**
		 * Represents the frustum window specification. This property should not be edited
		 * directly but via {@link PerspectiveCamera#setViewOffset} and {@link PerspectiveCamera#clearViewOffset}.
		 *
		 * @type {?Object}
		 * @default null
		 */
		this.view = null;

		/**
		 * Film size used for the larger axis. Default is `35` (millimeters). This
		 * parameter does not influence the projection matrix unless {@link PerspectiveCamera#filmOffset}
		 * is set to a nonzero value.
		 *
		 * @type {number}
		 * @default 35
		 */
		this.filmGauge = 35;

		/**
		 * Horizontal off-center offset in the same unit as {@link PerspectiveCamera#filmGauge}.
		 *
		 * @type {number}
		 * @default 0
		 */
		this.filmOffset = 0;

		this.updateProjectionMatrix();

	}
Constructs a new perspective camera.

@param {number} [fov=50] - The vertical field of view.
@param {number} [aspect=1] - The aspect ratio.
@param {number} [near=0.1] - The camera's near plane.
@param {number} [far=2000] - The camera's far plane.