Fresnel Flashlight

Purpose

To show an application of the Fresnel lens.

Equipment

Fresnel and normal flashlights.

Images

l6-55

Description

A "Fresnel flashlight" has a Fresnel lens covering the central area of the glass, causing light which would normally spread out over a large cone to be focused into a nearly parallel beam. Unfortunately, when you compare the light output of this Fresnel flashlight with that of a normal flashlight it really doesn't seem brighter. But it's a nice idea for peddling flashlights.