Telescope is an instrument that increases the periphery and visual sense of the eyes. When one decides on to buy a telescope one has to do meticulous homework in regards to the various technical aspects of the telescope and then zero into the one which would suit the specific needs. The need to understand the technicality arises from the fact that an amateur astronomer would not be wanting something which is an advanced space telescope and thus waste monetary resources.
A telescopes technicalities can baffle one and the decision as to which one is best suited to ones needs does not come easy. A veteran astronomer and an amateur astronomer would look for different features in their telescopes and thus understanding the functions and technicalities helps by fitting the right block at the right place.
Let’s take a look at the basic technical aspects that make a good telescope which can help one adjudge which telescope is best suited for his/her sphere of work:
The aperture of a telescope is basically the diameter of the mirror or the main lens of the telescope. The aperture determines how bright and sharp view one will get or to say- as the aperture of a telescope increases the view through it becomes sharper and brighter. This notion in literal sense would lead one into believing that, to have a good telescope just have the one with high aperture, but this contention is not true. When one is choosing the right telescope for himself/herself, one should take into consideration his scope of work and the fact that whether the telescope will suit the work environment. For instance if one buys a huge telescope, so as to have a good size of aperture and he/she needs to carry the telescope every-day to various places, then the decision would stand wrong. So what is important is to understand the work practise which one will follow and then choose a telescope with technical aspects best suited to individual needs.
Magnification or Power
The magnification capacities of a telescope is determined by the fact that how close a view of the celestial objects can the telescope offer. The power of the telescope to offer a good magnification is an important technical factor when one is choosing the right telescope for himself/herself, but the fact remains that it is not a decision making factor.
When an astronomer buys a telescope the sole aim which stands is to get a close look at their objects of interest, thus magnification capabilities of a telescope are critical to decision making, but the important aspect is that any telescope’s magnification power can be increased by using different eyepieces. These eyepieces are basically removable lenses which one looks into to get the view. When one buys a telescope he/she generally gets along with it a range of eyepieces and if not a variety of them are available in the market. So this technical aspect can be taken care of and is not much of a concern.
Though a fact remains that just using a high power eyepiece would not give you the desired magnification, till such time it is not supported by proper aperture. So if one uses a high power lens in a telescope with small aperture the view will be magnified but fuzzy. Thus while one chooses a telescope the various technical aspects should be well coordinated for best results.
As we know that all the cars perform the same task of transporting people from one place to another but what differentiates one brand from another is their design. Similarly among telescopes too the designing determines their portability, economies and visual sharpness. Telescopes with similar aperture can also differ in price and portability depending on their designs. Thus design of a telescope is a technical aspect which needs to be looked into while making the buying decision.
On basis of their designing, the telescopes are categorized into three categories:
1. The Refracting Telescope
In a refractor telescope, there is a thin, long tube through which the light passes from the front objective lens in a straight line, to the eyepiece at the opposite end. This is the most commonly used type of telescope and is very simple in design. The best part about this telescope is the fact that since the tube is sealed the optics are protected and little maintenance is required. A refracting telescope provides excellent views of planetary and binary stargazing.
These telescopes have an aperture of 3 to 5 inches and thus are not very suited for gazing distant galaxies. Their portability is also a matter of concern as they are quite bulky and long which restricts their practical use. The refracting telescopes are also quite a burden on the pockets.
2. The Reflecting Telescope
A reflecting telescope works on a different mechanism where a parabolic mirror is used instead of a lens to focus light to a flat secondary mirror, which in turn performs the task of reflecting the image out of an opening located at the main tubes side. This telescope has the advantages of easy construction and thus is easy to use. This telescope gives excellent view of remote galaxies and delivers good quality bright images. It is quite portable and is pretty economical.
Since the tube of this telescope are open in the air it catches dust easily requiring more handling care and maintenance. This telescope is not apt for terrestrial applications and this limits its scope of work.
3. Catadioptric Telescope
This is the most popular type of instrument, where a combination of lenses and mirrors is put to use to form an image. This type of telescope is compact, durable and versatile and provides excellent lunar and deep sky observations. On the other hand it generates a great pocket pinch and doesn’t have a very appealing appearance.
So these are the three kinds of designs for telescope which are segregated on the basis of their technical aspects. One should choose what best suits his/her personnel needs.
Mounting in crude terminology is the base on which a telescope stands, which helps in having that perfect view without any disturbance. Mounts for a telescope can be classified into two types:
THE EQUATORIAL MOUNT – This mount makes your tracking of motions quite swift and easy and is quite advantageous when one is aiming to find his/her way among the stars.
THE ALTAZIMUTH MOUNT – This mount is simpler as compared to equatorial mount giving an up-down, right-left motion. This mount is light in weight and quite low in cost.
These are some of the technical aspects which should be taken into consideration while one is deciding as to which telescope to buy. These technical aspects should be compared with the needs and work of the user, so that the ultimate choice of the telescope turns out beneficial for the one using it.