A reflector telescope uses a mirror to bounce the light back towards the eyepiece. The most popular design is a newtonian reflector, invented by Newton himself. It uses two mirrors. A large primary mirror located at the bottom end of an opened tube and bounces back the light upwards on a small mirror located near the top end of the tube (the end pointing to the sky). This secondary mirror is tilted at a 45 degree angle and redirects the light towards the eyepiece. There’s no glass refractor at all.
A “reflector telescope”, also called “reflecting telescope” gathers and reflects light with mirrors. The most popular design is a newtonian reflector, invented by Newton himself. It uses two mirrors. A large primary mirror located at the bottom end of an opened tube and bounces back the light upwards on a small mirror located near the top end of the tube (the end pointing to the sky). This secondary mirror is tilted at a 45 degree angle and redirects the light towards the eyepiece. There’s no glass refractor at all in this type of telescope, which makes cheaper to mass produce and thus more affordable for you.
A bit of history: Why Newton Created the Reflector Telescope
While the design of this type of telescope is credited to Newton, others before him explored this idea. Galileo Galilei had pondered using a mirror as the image forming objective soon after the invention of the refracting telescope. Newton just happen to be the one to actually build it.
In newton’s days, a common problem with the refracting telescopes was color distortion, also know as “chromatic aberrations”. Newton had a theory that white light is actually composed of a spectrum of colors, which we now know to be true. He speculated that when light passed through the glass of the refractor, it would break into a rainbow of colors and this caused the problem of cromatic abberations. His solution was to build a telescope that wouldn’t use the glass components so he came up with a telescope design that would use mirrors instead. In other words, he created the reflecting telescope to prove a theory, and in doing so he solved the problem of color distortions.
What is a Dobsonian Telescope?
A Dobsonion telescope, also called the “dobson telescope” or “dob telescope” is actually a newtionian reflector telescope. There’s nothing different about the deisng of the telescope per say. Rather, the innovation relates to the telescope mount. The two “skyquest” telescopes featured at the bottom of this page use a dobson mount.
In the 1960’s, John Dobson created a special mount that was practical for large telescopes. This Dobson mount was also mechanically simpler to build and this allowed for the cost effective mass production of larger telescopes. The most common type of telescope amonsgt backyard astronomers is the Dobsionian telescope. These larger telescopes are often called “light buckets” and they are particularly good for observing deep sky objects.
Why buy a Reflecting Telescope?
Newtonian reflectors are the ideal “all purpose” telescopes. Because the design is simple and they do not use glass components, they are cheaper to produce thus offer the best value for your money. A 6 inch refractor telescope would cost A LOT more than a 6 inch reflecting telescope. Reflectors can also be used in astrophotography, but they require a motorized mount for taking long exposure photos. Reflecting telescope bigger than 8 inches tend to be more difficult to transport.
Best Newtonian Reflector Telescopes (under $500)
|Orion SkyQuest XT8 Classic Dobsonian Telescope||Celestron NexStar 130 SLT Computerized Telescope|
Top Newtonian Reflecting Telescopes (under $2000)
|Orion SkyView Pro 8 GoTo Reflector Telescope|