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A zone plate is a device used to focus light or other things exhibiting wave character. [1] Unlike lenses or curved mirrors , zone plates use diffraction instead of refraction or reflection . Based on analysis by French physicist Augustin-Jean Fresnel , they are sometimes called Fresnel zone plates in his honor.
The light colour is usually white and the dark colour may be painted – in which case black is typical – or left unpainted if the road surface itself is dark. The stripes are typically 40–60 cm (16–24 in) wide. [citation needed] Sometimes, zebra crossings are placed on a speed bump, meaning the zebra crossing is level with the pavement ...
The camera was fully manual, with a built-in CdS light meter. The battery was only for the metering circuit. The user needed to push a button on the front of the camera to close the aperture, and then set the aperture ring on the lens to a value where the meter needle would fit inside a marker ring.
75mm - 150mm mm f/4.5 MACRO switch on lens side, zoom lens for medium format, Manual / Auto switch (Hasselblad mount) The Variogon is a zoom lens. 60-140mm f/4.6 AF (for Rollei 6000)
These connectors include components such as ferrules and alignment sleeves for precise fiber alignment. Quality connectors lose very little light due to reflection or misalignment of the fibers. Optical fiber connectors are categorized into single-mode and multimode types based on their distinct characteristics.
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