Virtual image

A virtual image is formed where diverging light rays appear to originate after reflection or refraction, although the rays do not actually converge there.

Ray tracing: A geometric method that predicts light paths using lines directed along rays. Backward extensions of outgoing rays locate where a virtual image appears.
Geometric optics: The model of light as rays traveling along paths governed by reflection and refraction. Virtual images are located using the ray model rather than wavefront calculations.
Magnifying glass: A converging lens used to produce an enlarged view of a nearby object. With the object inside the focal length, it presents an enlarged virtual image.
Real image: An optical image formed where light rays actually converge after reflection or refraction. Unlike a virtual image, it can generally be projected onto a screen at its image location.
Plane mirror: A flat reflecting surface that forms an upright image the same distance behind it as an object stands in front. Its reflected rays diverge as if they came from behind the mirror.
Reflection: The change in a light ray’s direction when it encounters a boundary and returns to its original medium. Mirrors create virtual images by redirecting rays toward an observer.
Rear-view mirror: A vehicle mirror that lets a driver observe areas behind the vehicle. Its convex surface forms upright virtual images across a broad field of view.
Image plane: A plane where an optical system forms a focused image of an object. A real image lies at a physical convergence plane; a virtual image does not.
Concave mirror: A spherical mirror whose reflecting surface curves inward toward its center of curvature. It forms a virtual image when the object lies between the mirror and its focal point.
Refraction: The change in a wave’s direction as it passes between materials where its speed differs. Lenses bend rays so their backward extensions can mark a virtual image.

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