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The double-Amici prism is a symmetric form of the more general triplet prism, in which the apex angles and glasses of the two outer elements may differ (see the figure at right). Although triplet prisms are rarely found in optical systems, their added degrees of freedom beyond the double-Amici design allow for improved dispersion linearity.
Galilean type Soviet-made miniature 2.5 × 17.5 monocular Diagram of a monocular using a Schmidt-Pechan prism: 1 – Objective lens 2 – Schmidt-Pechan prism 3 – Eyepiece. A monocular is a compact refracting telescope used to magnify images of distant objects, typically using an optical prism to ensure an erect image, instead of using relay lenses like most telescopic sights.
Recumbent or prism glasses are glasses that use a prism with a 90° refraction to allow the wearer to read or view a screen while lying on their back. Developed by Liverpudlian ophthalmologist Andrew McKie Reid in the 1930s to assist people bedbound by chronic illness or spinal injury, recumbent glasses have more recently been marketed not ...
The deck prism laid flush into the deck, the glass prism refracted and dispersed natural light into the space below from a small deck opening without weakening the planks or becoming a fire hazard. In normal usage, the prism hangs below the overhead and disperses the light sideways; the top is flat and installed flush with the deck, becoming ...
The glasses from this period contain high levels of barium oxide and lead, distinguishing them from the soda–lime–silica glasses of Western Asia and Mesopotamia. [27] At the end of the Han Dynasty (AD 220), the lead-barium glass tradition declined, with glass production only resuming during the 4th and 5th centuries AD. [ 28 ]
Didymium glasses. Didymium (Greek: δίδυμο, twin) is a mixture of the elements praseodymium and neodymium.It is used in safety glasses for glassblowing and blacksmithing and filter lenses for flame testing, especially with a gas ()-powered forge [why?], where it provides a filter that selectively blocks the yellowish light at 589 nm emitted by the hot sodium in the glass without having a ...