How long does it take to
collimate a Schmidt-Cassegrain?
This device-unlike those using mirrors, diffractive lenses, or glass tubes to
collimate beams (SN: 6/27/92, p.
Modern commercial spectrographs typically combine one or more curved optical elements, whether reflective mirrors or refractive lenses, which
collimate light to and focus dispersed light from a dispersive element onto a focal plane array detector.
Because tungsten is extremely dense at 71% heavier than lead, it is used in medical applications, such as grids used to
collimate and attenuate stray x-rays in CT scanners, and ID tags used in implanted medical devices.
Designated the OPB733TR device, the infrared sensor uses a lensed IR LED and phototransistor elements to
collimate the light beam, giving the device an optimizing detection range from 0.4" to 1.0" (10 to 25.4 mm).