The main difference between refracting and reflecting telescopes lies in how they gather and focus light.
- Refracting Telescope (Refractor):
- Lens-based: It uses lenses to gather and focus light. The primary lens at the front of the telescope collects the light and brings it to a focus.
- Design: A refractor typically has two main lenses – the objective lens (to collect light) and the eyepiece lens (to magnify the image).
- Chromatic Aberration: Refractors can suffer from a phenomenon called chromatic aberration, where different colors of light are focused at different points, causing color fringing around objects, especially bright ones.
- Example: The Galileo telescope is a famous refractor.
- Reflecting Telescope (Reflector):
- Mirror-based: It uses mirrors instead of lenses to gather and focus light. The primary mirror reflects light onto a secondary mirror, which then directs the light to the eyepiece.
- Design: The most common configuration is the Newtonian reflector, where light is collected by the primary mirror and directed to a secondary mirror that reflects it to the eyepiece.
- No Chromatic Aberration: Since mirrors reflect all wavelengths of light equally, reflecting telescopes do not suffer from chromatic aberration.
- Example: The Hubble Space Telescope is a type of reflecting telescope.