Real and Virtual Images

Images formed by mirrors and lenses can be either real or virtual.

Real images

A real image is formed where light rays actually converge (meet). It can be projected onto a screen.

Properties:

• Formed by converging rays.
• Can be captured on a screen or photographic film.
• Always inverted (upside down) relative to the object.
• Formed by concave mirrors and converging lenses (when the object is beyond the focal point).

Virtual images

A virtual image is formed where light rays appear to come from but do not actually meet. It cannot be projected onto a screen.

Properties:

• Formed by diverging rays that are extended backward.
• Cannot be captured on a screen.
• Always upright (same way up as the object).
• Formed by plane mirrors, convex mirrors, and converging lenses (when the object is between the lens and the focal point).

Comparison

Property	Real image	Virtual image
Ray convergence	Rays actually meet	Rays appear to diverge from a point
Screen projection	Can be projected	Cannot be projected
Orientation	Inverted	Upright
Examples	Cinema projector, camera, eye	Plane mirror, magnifying glass

The plane mirror

A plane mirror always produces a virtual image that is:

• The same size as the object.
• The same distance behind the mirror as the object is in front.
• Laterally inverted (left and right are swapped).
• Upright.

Common errors and how to correct them

• Thinking virtual images are “not real” or “imaginary.” Virtual images are visible to the eye; they just cannot be projected onto a screen.
• Confusing “inverted” with “laterally inverted.” Inverted means upside down; laterally inverted means left-right swapped.

How to apply this in an exam

State whether the image is real or virtual. Describe its properties: orientation, size relative to the object, and whether it can be projected.