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Visual autocollimators are often used for aligning laser rod ends and checking the face parallelism of optical windows and wedges. Electronic and digital autocollimators are used as angle measurement standards, for monitoring angular movement over long periods of time and for checking angular position repeatability in mechanical systems.
The light from stars (other than the Sun) arrives at Earth precisely collimated, because stars are so far away they present no detectable angular size.However, due to refraction and turbulence in the Earth's atmosphere, starlight arrives slightly uncollimated at the ground with an apparent angular diameter of about 0.4 arcseconds.
A Cheshire eyepiece or Cheshire collimator is a simple tool that helps aligning the optical axes of the mirrors or lenses of a telescope, a process called collimation. It consists of a peephole to be inserted into the focuser in place of the eyepiece. Through a lateral opening, ambient light falls on the brightly painted oblique back of the ...
Example of a particle collimator. A collimator is a device which narrows a beam of particles or waves. To narrow can mean either to cause the directions of motion to become more aligned in a specific direction (i.e., make collimated light or parallel rays), or to cause the spatial cross section of the beam to become smaller (beam limiting device).
The collimated transmission method has been used to measure the optical properties of biological tissues since the early 1980s. A collimated light source was generated by a laser or with a diffuse source and a collimator. Unscattered light transmission through the tissue was detected and Beer's law was used to estimate the extinction ...
Autocollimation is an optical setup where a collimated beam (of parallel light rays) leaves an optical system and is reflected back into the same system by a plane mirror.. It is used for measuring small tilting angles of the mirror, see autocollimator, or for testing the quality of the optical system or of a part of it.
Normally these impact shifts are insignificant, but accuracy-oriented users, who wish to use their telescopic sight trouble-free at several magnification levels, often opt for FFP reticles. Around the year 2005 Zeiss [ 27 ] was the first high-end European telescopic sight manufacturer who brought out variable magnification military grade ...
Powerful laser guide star system at the Paranal Observatory. The actual laser guide star is the small spot above the apparent end of the laser beam. A laser guide star is an artificial star image created for use in astronomical adaptive optics systems, which are employed in large telescopes in order to correct atmospheric distortion of light (called astronomical seeing).