PURPOSE: To show an application of the Fresnel lens.
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.
REFERENCES: (PIRA unknown.)
EQUIPMENT: Fresnel and normal flashlights.
SETUP TIME: None.
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