Table of Optics Demonstration

List of Optics Equipment & Supplies

Lecture Demonstrations

Soap Film Interference, 6D30.20

Topic and Concept:

pira200 Listed


SoapFilm1.jpg SoapFilm2.jpg


Glycerin film in circular wire frame, oriented vertically, is illuminated by white light. The thickness of the glycerin varies in the vertical direction due to the action of gravity (thinner at top, thicker at bottom). Thin-film interference causes horizontal bands of color to appear.



ID Number


OP, Bay B4, Shelf #1

tabletop camera

Setup and Procedure:

  1. If demonstration hasn't been used in a while, water may have evaporated, leaving glycerin too thick to make a film. Dilute with tap water if necessary.
  2. Set up demonstration on table so that open side of box faces white board; turn on white board lights. You should see pretty horizontal bands of color.
  3. Set up table top camera at same height above table as film, and project camera view onto screen.


fw: SoapFilmInterference (last edited 2018-07-19 16:31:19 by srnarf)