How do refracting telescopes and reflecting telescopes differ?

Refracting and reflecting telescopes differ primarily in how they collect and focus light to produce an image.

Refracting Telescopes

Commonly called refractors, these instruments use a lens (the objective) to gather light. The name is derived from refraction, the process by which light bends as it passes through the glass objective lens to converge at a focal point. A major limitation of this design is chromatic aberration, where different colors of light fail to focus at the same point, potentially causing color distortion in the image.1

Reflecting Telescopes

Reflectors use a concave primary mirror to collect and focus light. Because reflected light does not disperse according to wavelength, these telescopes are not subject to chromatic aberration. Reflectors offer several practical advantages:2
* Design Efficiency: The telescope tube is typically shorter than that of a refractor with the same aperture, making the housing dome more economical to construct.2
* Versatility: They can explore regions of the electromagnetic spectrum beyond visible light, including ultraviolet and infrared wavelengths.2
* Mirror Support: Unlike lenses, which must be supported at their edges, the primary mirror of a reflector is supported from the back, allowing for larger, more stable designs.2