Reflektoritähystimiä

Reflektoritähystimiä, known in English as reflecting telescopes or reflectors, are optical instruments that use mirrors to form an image of a distant object. Unlike refractors, which use lenses, reflectors employ one or more curved mirrors to gather and focus light. The primary mirror, usually a concave parabolic or spherical surface, collects incoming light and reflects it to a focal point. A secondary mirror then redirects this light to an eyepiece or detector, where the observer or instrument can view the image.

The most common type of reflecting telescope is the Newtonian reflector, invented by Sir Isaac Newton. In this design, a secondary flat mirror is placed at a 45-degree angle within the telescope tube to intercept the light cone from the primary mirror and direct it out the side of the tube to the eyepiece. Another popular design is the Cassegrain reflector, which uses a secondary convex mirror to reflect the light back through a hole in the center of the primary mirror. This configuration allows for a longer focal length in a more compact tube.

Reflecting telescopes offer several advantages. They are not subject to chromatic aberration, a phenomenon where different colors of light are focused at slightly different points by lenses, leading to color fringing. Mirrors can also be made much larger than lenses, allowing for the construction of very powerful telescopes capable of observing faint and distant celestial objects. This makes them indispensable tools for astronomical research and amateur stargazing alike.