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Lesson: Chapter 5 — Optics

5.4.3. The magnifying glass and other instruments 1 of 2

The magnifying glass

Hold a small object closer to a convex lens than its focal length, look through the lens, and the object looks bigger. That is a magnifying glass.

A small object just inside the focus of a convex lens; the rays spread after the lens, and traced back, dashed, they meet at a larger upright virtual image further from the lens on the object's side — what the eye sees.

After Figure 5.46.

Magnifying glass (simple microscope)

A convex lens fitted in a handle is a hand lens or magnifying glass, also called a simple microscope.

Magnifying glasses are used to look closely at small insects, parts of flowers and other small things.

Inside the focal length

It only magnifies like this with the object inside the focal length. Move the lens further away and the image turns upside down — that is the real image of the earlier pages.