Draw a ray which passes from the object through the centre of the lens. Some ray diagrams may also show a third ray. Peep holes contain concave lenses. They are set into doors so the occupant can ...

A spyglass with a plano-convex lens that focuses at 12 inches and a plano-concave lens that focuses at four inches, he found, magnifies images three times (12 divided by four). Galileo played with ...

the image formed is virtual, erect and magnified. When used to see objects magnified, the convex lens is called a magnifying glass. ⇒ A concave lens always forms erect, virtual and smaller image ...