List of telescope parts and construction

Accessories

• Finderscope
• Iron sight
• Reflector (reflex) sight
• Cheshire collimator: A simple tool to collimate a telescope

Control

• Clock drive
• GoTo

Mechanical construction

• Mirror support cell
• Serrurier truss
• Silvering

Mounts

• Telescope mount - Types include:
  • Altazimuth mount
  • Equatorial mount
    • Equatorial platform
      • Poncet Platform
    • Fork mount
    • German equatorial mount
    • Springfield mount

Optics

Mirrors and lenses are the critical light-bending components of a telescope.

• Objective: The first lens or curved mirror that collects and focuses the incoming light.
  • Primary lens: The objective of a refracting telescope.
  • Primary mirror: The objective of a reflecting telescope.
• Corrector plate: A full aperture negative lens placed before a primary mirror designed to correct the optical aberrations of the mirror.
  • Schmidt corrector plate: An aspheric-shaped corrector plate used in the Schmidt telescope.
  • Meniscus corrector: A meniscus-shaped corrector plate usually used in the Maksutov telescope.
• Focusing mask: A full aperture mask temporarily placed before the primary mirror to aid in focusing the telescope.
  • Bahtinov mask
  • Carey mask
  • Hartmann mask
• Sub-aperture corrector: One or a series of corrective lens (sometimes combined with a corrective curved mirror) placed after (near the focus) a primary mirror designed to correct the optical aberrations of the mirror. These can be just a small version of the corrector plate, but since they are usually used in a Cassegrain configuration in front of the secondary mirror they require additional modification since the light passes through them twice.
• Secondary mirror
• Mirror#Instruments
• Curved mirror
• Honeycomb mirror
• Liquid mirror
• Parabolic reflector

Subsequent (sometimes optional) components realign, segment, or in some way modify the light of an incoming image:

• Field lens: A correcting lens placed just before the image plane of a telescope.
• Telecompressor or focal reducer: Optical element to decrease the telescope's focal length and magnification (usually by a fixed percentage) and widen the field of view, providing opposite effects of a Barlow lens.
• Star Diagonal: Used to change the angle of the light coming out of a telescope, for easier viewing.
• Herschel Wedge: Similar to a star diagonal with a wedge-shaped unsilvered prism reflector that reduces incoming light by up to 95% for solar viewing.
• Coma corrector a correcting lens used to reduce coma distortion in fast reflecting telescopes.
• Field flattener a correcting lens used to reduce field curvature in refracting telescopes for atrophotography.
• Barlow lens: Optical element to increase the telescope's focal length and magnification, narrow the field of view and reduce coma distortion, providing opposite effects of a telecompressor.
• Astronomical filter: Used to select specific colors (or light frequencies) for astrophotography.
• Filter wheel: One manner to easily insert filters into the optical train. Mostly used for photography.
• Focuser: Allows the user to adjust the focus by moving the eyepiece along the optical axis.
• Eyepiece: Performs the final focus correction before the light reaches the eye.
• Charge-coupled device (CCD): A light-sensitive integrated circuit digital sensor (commonly used in digital cameras) that turns light into an electrical charge used to collection image data.

Generally applicable to all items:

• Metallizing: A way of coating mirrors for high-efficiency light reflection.
• Optical coating: Thin layers applied to mirrors, filters, and lenses to avoid reflections, as well as absorb certain colors.