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Materials and Equipment
Ideas for Inexpensive Optics Equipment
Color Filters. You can get a booklet with 100 color filters for about $10 plus shipping. A search on "color filter booklet" should turn up multiple sources. With a filter booklet and three small flashlights you can do experiments on combination and perception of color.
Lens Mounts. You can make inexpensive lens mounts (holders) using PVC pipe fittings from your local hardware store (e.g., an adaptor that has a socket on one side, and a male thread on the other). Pipe fittings with 1 inch internal diameter will work for lenses with 25 mm diameter; pipe fittings with 1.5 inch internal diameter will work for lenses with 38 mm diameter. The lens can be held in place with a short length of PVC pipe of the appropriate diameter. Just press-fit the pipe in place, in case you want to remove the lens later.
Light Sources.
Laser pointers. Red laser pointers are an inexpensive source of monochromatic light. Prices start at about $10. Green laser pointers are more expensive (at least $55), but can make an interesting comparison to red lasers for projects involving diffraction, scattering and absorbance.
Mini Maglites. These are small flashlights with a focusing mechanism for the beam, which makes them a good choice for an inexpensive white-light source.
Optical Bench. If you use a single size of PVC pipe fittings as lens mounts (see above), then you can use a V-shaped channel made from angled aluminum to support them. This way you can experiment with combinations of optical elements. Support the channel with wood blocks cut at 45 degrees. Measure positions with a tape measure.
Positive and Negative Lenses. You can purchase inexpensive lens demonstration sets with 6 sample lenses in 38 mm or 50 mm diameter (depending on how hard you look, anywhere from $5–$20, plus shipping). A search for "lens demonstration set" or "plano-convex lens" should turn up several different sources. If you need lenses with a specific focal length for your project, try searching for "surplus optics" to get better prices. See the Lens Mounts section above for an inexpensive method for mounting 25- and 38-mm diameter lenses.
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