
Dichroic filters separate light by selective transmission and reflection depended on the wavelength. These examples are 69 x 97 mm (about 2-11/16" x 3-7/8") x about 1.8 mm thick. The "yellow" filter TRANSMITS yellow, and reflects all other colors. (Reflections therefore have a violet hue.) Good for lab demonstrations or projects, possibly for photography too.
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22253 YELLOW DICHROIC FILTER |
One wiseacre assumed we meant any package leaving our shipping room that once had a glass object in it. That is a malicious rumor. . . Ground glass is thin plate glass, the surface of which has been physically ground or acid-etched to create a grainy, grayish, opaque surface. Use it to produce an image from a lens or lens system. Even a simple magnifier, held between the ground glass and, say, a window, will produce an image of the window scene on the ground glass. Ground glass has another magical property: it is opaque to any object viewed at a distance, but not if that object is in direct contact with the glass surface. A necessary element of your optical education. #2728 (square) is 2"sq x 1/32" thick. #2610 (rectangular) is 3-1/2" x 4-3/8" x 1/16" thick.
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2610 RECT. GND. GLASS | |
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2728 SQUARE GND. GLASS |
Okay, polarizing filters for the literal minded. Each filter is a 20 mm dia x 2 mm think piece of glass with a couple of tiny slots in the edge. Each has 20% transmission by itself, which may not sound like much, but is about what you get through decent sunglasses. We are selling a pair so you can do experiments on transmission as you rotate one against the other to reduce the light getting through virtually to nothing. Or you can make some very cool granny sun glasses if that turns you on. The big guys get upwards of $7.00 per filter for these dudes!! Isn't surplus cool??
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26970 POLARIZING FILTERS |
A little pricey for a 2" x 2" x 1/8" thick piece of clear glass, until you figure that this is pretty darned talented glass, and that it filters heat and reflects infrared and ultraviolet rays. Then it's a bargain!
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34410 HEAT FILTER |
Al Luebbers, our founder, collected glass. Not glass like you'd find on a knick-knack shelf, but optical glass. Lenses, prisms, reticles and filters, for example. Focus on the filters. Many of his filters came out of military surplus, and this is for-real stuff. We mean many are solid dyed optical glass, ground and polished to flatness standards that were probably excessive. Others are from the old days in photographic optics, and their standards were even tighter than your militaristic Uncle's. We've found that photographers, artists, and optical designers still have an occasional need for good glass filters, so we're making a list of some goodies. As always, don't be timid about calling for quotes on quantities. If we have 'em, we'll sell 'em. Just don't sell them back. Please! If you're just playing, the assortment set may be a better way to go. Can't decide?? New to filters?? Doing a science project on light?? Let us assort (6) different filters of at least 20mm. dia for you.
| DIAM.or SIZE (mm) | CENTER THICK (mm) | |||
|---|---|---|---|---|
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3477 FILTER, AMBER | 26 | 1.5 | |
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3492 FILTER, AMBER | 30 | 2.3 | |
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3480 FILTER, NEUTRAL | 26 | 1.5 | |
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3490 FILTER, NEUTRAL | 30 | 2.3 | |
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3510 FILTER, NEUTRAL | 50x54 | 3.1 | |
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3512 FILTER, NEUTRAL | 67x70 | 4.1 | |
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3458 FILTER, RED | 6 | 1.4 | |
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3464 FILTER, TYPE A | 9 | 1.8 | |
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3470 FILTER, YELLOW | 18x18 | 1.6 | |
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3504 FILTER, YELLOW | 37 | 5.5 |
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