peilitähystimien

Peilitähystimet, also known as reflecting telescopes or reflectors, are optical instruments that use mirrors to form an image of a distant object. Unlike refractors, which use lenses, mirrors do not suffer from chromatic aberration, meaning they can focus all colors of light at the same point without color fringing. This makes them particularly well-suited for observing faint celestial objects and for astronomical photography.

The primary mirror in a peilitähystin is a concave mirror, typically parabolic in shape, which collects and reflects light. This reflected light is then directed to a secondary mirror, which redirects the light path to the eyepiece or camera. There are several common designs for peilitähystimet, including the Newtonian, Cassegrain, and Schmidt-Cassegrain. The Newtonian telescope, invented by Isaac Newton, is one of the simplest and most common designs, using a flat secondary mirror placed at a 45-degree angle to the optical axis. Cassegrain telescopes use a convex secondary mirror to reflect light back through a hole in the center of the primary mirror, resulting in a more compact design. The Schmidt-Cassegrain is a hybrid design that uses a corrector plate at the front of the tube to correct for aberrations, allowing for a very compact and powerful instrument.

Peilitähystimet are widely used by amateur astronomers and in professional observatories. Their ability to gather a large amount of light makes them ideal for viewing faint galaxies, nebulae, and star clusters, as well as for detailed observation of planets. The size of the primary mirror is the most crucial factor determining a peilitähystin's light-gathering ability and resolution.