The Pros and Cons of Reflector Telescopes
There are two basic varieties of telescopes for the backyard observer, reflector telescopes and refractor telescopes, and they are different in the way they gather and focus light onto the eyepiece. The class of telescope discussed in this post will be the reflector telescopes. These telescopes use a series of large and small mirrors to bend and amplify the starlight from the stars and planets. It’s hard to imagine that merely by utilizing mirrors gives us the ability to view the dust rings of Saturn, the moons of Jupiter or the pinwheels of remote galaxies – but that is how it works.
There are two simple designs of reflector telescopes – the Newtonian and the Cassegrain. The Newtonian type was first created by Sir Issac Newton, the famous physicist of the seventeenth century. He concluded from his work in optics that the ground glass lenses of the period always suffered from the prismatic dispersion of white light into colors. This is called chromatic aberration. In 1668 he developed the first Newtonian Telescope utilizing a mirror as the objective instead of a ground glass lens to bypass the difficulty of the chromatic aberration. This design is rather straightforward and quite well-liked by entry level astronomers. There is usually one big mirror at the bottom of the telescope tube which concentrates the celestial image onto a different flat mirror that then transmits the picture to the eyepiece where it will be magnified.
The second type of reflector telescope is the Cassegrain type. This design utilizes a main concave mirror at the base of the telescope with a convex subsequent mirror facing it at the top of the tube. The starlight comes in through the top of the telescope where it is reflected by the primary mirror on to the more compact mirror. This mirror then transmits the starlight back through a gap in the primary mirror to the eyepiece. This design of reflector telescope is somewhat more complex and thus more expensive, but both do the job really well.
Benefits Of Reflector Telescopes
The reflector telescope is a good all-around telescope and has several positive aspects over the refractor telescopes. On the pro side, the layout of reflector telescopes is somewhat less intricate than that of refractor telescopes. This typically can make these telescopes less expensive, at least on the lower end. In addition this allows far more magnifying power in a more compact design. The more advanced models seriously give a lot more power for the money in contrast to refractor telescopes. The fast focal ratio can make reflector telescopes quite efficient for seeing faint celestial objects deep in space.
Negatives Of Reflector Telescopes
Although the reflector telescope is a good all-around telescope especially for the novice astronomer, it is not without most drawbacks. The alignment of the mirrors is somewhat delicate and transport can be a problem if not performed quite carefully. The mid-size to larger versions of these telescopes have a tendency to be bulkier compared to the refractor telescopes of the same power. The entry level models tend to create a somewhat distorted picture and there is a considerable amount of upkeep involved in cleaning and aligning the mirrors as these telescopes are not closed systems.
As with any telescope, there are constantly advantages and disadvantages to take into account when looking to buy. The reflector telescopes are efficient and easy to use making them the best deal for amateur stargazers. It is undoubtedly beneficial to consider a reflector telescope when you are deciding which telescope will be best for you.