What is a Real Image?
A real image is an optical image formed where light rays actually converge and intersect after reflecting off a mirror or passing through a lens. Because the light rays physically meet, a real image can be projected onto a screen and is always inverted relative to the object.
What is a Virtual Image?
A virtual image is an optical image formed where light rays appear to diverge from a point, but do not actually converge or intersect. These images cannot be projected onto a screen because the light rays only seem to originate from that point; they do not physically pass through it. Virtual images are typically upright.
Key Distinctions in Formation and Properties
The fundamental difference lies in light ray convergence: real images form when rays physically converge, while virtual images form when rays only appear to diverge from a point. Real images are always inverted and can be projected, whereas virtual images are upright (relative to the object for single lenses/mirrors) and cannot be projected. Furthermore, real images are typically formed by converging lenses or concave mirrors when the object is beyond the focal point, while virtual images are formed by diverging lenses, convex mirrors, or when an object is within the focal point of a converging lens or concave mirror.
Practical Examples and Applications
Common examples of real images include those produced by a projector onto a cinema screen or the image formed on the retina of your eye by its lens system. Virtual images are what you see when you look at yourself in a plane mirror, or the magnified view through a magnifying glass. Understanding these distinctions is crucial in designing optical instruments, from cameras and telescopes to microscopes and eyeglasses.