A type of reflecting telescope where the beam reflected by the primary mirror is reflected by a flat secondary mirror so that the focus falls to the side of the telescope tube.
A telescope design originated by Isaac Newton. In such a telescope, light enters the front of a long tube, is reflected by a parabolic mirror, so that it returns to the front of the tube, and then reflects off a flat mirror, tilted at a 45 degree angle, so that it passes through a hole in the side of the tube, where it can be viewed with an eyepiece. Newtonian telescopes have an advantage over refractors, which involve lenses, because mirrors reflect all kinds of light at exactly the same angle, and do not suffer from chromatic aberration. They have a disadvantage over catadioptric telescopes, in which the secondary mirror (the one at the front) is curved, in that they have a relatively long tube, for a given focal length.
A type of reflecting telescope with a parabolic primary mirror and a small secondary mirror angled at 45 degrees to deflect the focus of the primary to a position outside the tube near the top of the telescope. Newtonian telescopes were developed by Sir Isaac Newton.
A reflecting telescope in which incoming light is intercepted before it reaches the prime focus and is deflected into an eyepiece at the side of the instrument.
reflecting telescope in which the image is viewed through an eyepiece perpendicular to main axis
a simple reflecting telescope, and they tend to be large in diameter with a higher focal length
reflecting telescope with a paraboloidal primary mirror, and a flat elliptical diagonal secondary mirror that directs the focal plane out of the side of the telescope tube.
These telescopes have two mirrors. The light comes in through the aperture and then strikes the first mirror. It is then reflected back towards the aperture. The light strikes a diagonally placed mirror and diverts the light out of the main barrel of the telescope, where it comes to a focus at the eyepiece. See also, Cassegrain and Schmidt.
A reflecting type telescope with a 45° mirror, so that the primary image is observed through a hole in the side of the tube.
A reflector telescope that uses a a mirror set in the lower end of a tube. A small, secondary mirror near the upper end of the tube reflects the beam to the eyepiece.
A common type of reflecting telescope with a mirror objective and an open-end tube; named for Isaac Newton, who invented it.
a telescope in which the objective lens has been replaced by a concave mirror (see figure 23.11)
reflecting telescope in which a small plane mirror reflects the convergent beam from the objective to an eyepiece at one side of the telescope. After the second reflection the rays travel approximately perpendicular to the longitudinal axis of the telescope. See Cassegrain telescope.
The Newtonian telescope is a type of reflecting telescope invented by the British scientist Sir Isaac Newton (1643-1727), using a parabolic primary mirror and a flat diagonal secondary mirror.