Meade DS-2000 instruction manual Eyepiece, Element, Refracting Telescope, Reflecting Telescope

Refracting Telescopes use a large objective lens as their primary light-collecting element. Meade refractors, in all models and apertures, include achromatic (2-element) objective lenses in order to reduce or virtually eliminate the false color (chromatic aberration) that results in the telescopic image when light passes through a lens.

Reflecting Telescopes use a concave primary mirror to collect light and form an image. In the Newtonian type of reflector, light is reflected by a small, flat secondary mirror to the side of the main tube for observation of the image.

Eyepiece
F
	2-Element
Refracting Telescope	Objective Lens

In the refracting telescope, light is collected by a 2-element objective lens and brought to a focus at F.

Secondary

Mirror

Concave Mirror

F

Reflecting Telescope Eyepiece

In contrast, the reflecting telescope uses a concave mirror for this purpose.