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The mirror landing aid was a gyroscopically controlled concave mirror on the port side of the flight deck. On either side of the mirror was a line of green coloured "datum lights". A bright orange "source" light was shone into the mirror creating the "ball" (or "meatball" in later USN parlance) which could be seen by the aviator who was about ...
a snow effect slide can add snow to another slide (preferably of a winter scene) by moving a flexible loop of material pierced with tiny holes in front of one of the lenses of a double or triple lantern. [65] Mechanical slides with abstract special effects include: Slide with a fantoccini trapeze artist and a chromatrope border design (c. 1880)
The projection unit in a typical HUD is an optical collimator setup: a convex lens or concave mirror with a cathode-ray tube, light emitting diode display, or liquid crystal display at its focus. This setup (a design that has been around since the invention of the reflector sight in 1900) produces an image where the light is collimated , i.e ...
A concave mirror, or converging mirror, has a reflecting surface that is recessed inward (away from the incident light). Concave mirrors reflect light inward to one focal point. They are used to focus light. Unlike convex mirrors, concave mirrors show different image types depending on the distance between the object and the mirror.
Rear Admiral Hilary Charles Nicholas Goodhart CB FRAeS (28 September 1919 – 9 April 2011) was an engineer and aviator who invented the mirror-sight deck landing system for aircraft carriers. He was also a world champion and record breaker in gliding .
Foucault test setup to measure a mirror. The Foucault knife-edge test is an optical test to accurately measure the shape of concave curved mirrors. It is commonly used by amateur telescope makers for figuring primary mirrors in reflecting telescopes. It uses a relatively simple, inexpensive apparatus compared to other testing techniques.
Light path in a Cassegrain reflecting telescope. The Cassegrain reflector is a combination of a primary concave mirror and a secondary convex mirror, often used in optical telescopes and radio antennas, the main characteristic being that the optical path folds back onto itself, relative to the optical system's primary mirror entrance aperture.
As with objective lenses, a condenser lens with a maximum numerical aperture of greater than 0.95 is designed to be used under oil immersion (or, more rarely, under water immersion), with a layer of immersion oil placed in contact with both the slide/coverslip and the lens of the condenser. An oil immersion condenser may typically have NA of up ...