Reflecting Telescope Sources:
Reflecting Telescopes are used to view sky objects such as planets, the moon, star clusters, galaxies, nebulae, and multiple star systems.
Hollow Tube – Provides the structure of the telescope
Glass Lens – Allows source light into the tube
Parabolic Concave Mirror – Reflects source light to focal point
Secondary Flat Mirror – Reflects light at focal point to eyepiece
Eyepiece – Light and image is reflected here
Focuser – Adjusts the focus of the image at eyepiece
- Reflecting telescopes do not suffer from chromatic aberration.
- Figuring a mirror requires polishing only one precise surface rather than two (or four for a compound lens).
- Mirrors are easier to support because they can be supported on the sides and the back; large lenses tend to sag because they can only be supported on the perimeter.
- Great for viewing faint objects such as galaxies and nebulae, clusters, planets, the moon and binaries.
- Reflecting telescopes are large and bulky
- They require periodic maintenance to keep mirrors aligned
These telescopes were first conceived by Sir Isaac Newton. They use mirrors to gather and focus light to an eyepiece. Reflecting Telescopes use a primary parabolic concave mirror opposite the light source to focus light back at the source. At the concave mirrors focal point is another flat mirror which reflects image at a 90 degree angle to the eyepiece.