Meade Instruments DS-2000 LNT - Manual (Page 2)

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.
In the refracting telescope, light is collected by a 2-element objective
lens and brought to a focus at F.
In contrast, the reflecting telescope uses a concave mirror for this
purpose.
F
Eyepiece
2-Element
Objective Lens
F
Eyepiece
Concave
Mirror
Secondary
Mirror
Refracting Telescope
Reflecting Telescope