ECE532 Biomedical Optics
© 1998 Steven L. Jacques, Scott A. Prahl
Oregon Graduate Institute

EXAMPLE: Radiance of a flashlight

Consider again our cheap flashlight example.

The flashlight projects a beam that is 200 mW over its 3-cm diameter face and projects a 10-cm circle on a wall 25 cm distant. Assume that the lamp source behaves as a point source of light located at a virtual position 10.7 cm behind the face of the flashlamp. What is the radiance at the wall?

The geometry of the problem is:

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