Saturday, January 8, 2011

How i chose my first telescope


From what i remember, i started off browsing products lists of various telescope manufacturers like Meade, Celestron, Orion etc. It was helpful as i got to know about all of their products. I had studied about the three types of telescopes before i.e. The Refractor, Reflector and Cassegrain.

The Refractor Telescope
Its called the refractor telescope because it achieves magnification by refraction. This was what was earlier known as the 'spyglass' and was invented by Hans Lippershey, to whom the credit of inventing the telescope is awarded. These are the oldest type of telescopes, used by Galileo and others, till Sir Issac Newton invented the newtonian reflector. Well a lot can be written about the construction and working of refractor here but it is out of the scope of this journal. I studied them for information and better understanding and concluded that they have these advantages and disadvantages, well summarized at this link: Advantages and disadvantages of refracting telescope.

So refractors are rugged, more weather proof, easy to maintain and give more steady and sharper images. But, i was a buyer of limited resources. If i could i would have bought the best schimdt cassegarin telescope worth many grands. This brought me to consider the next type of telescopes, the reflectors.


The Reflecting Telescope 
Yes, it achieves magnification by reflecting, and for reflection we need a mirror. So it has a concave mirror (primary mirror) in one end which collects the light and focues on a secondary mirror which reflects it to the eyepiece. I studied about them too and made the following conclusions, summarized at this link: Advantages and disadvantages of reflecting telescope.

So reflectors are without chromatic aberration, and are cheaper than refractors of the same size and can be made bigger. 
Considering the above aspects a reflector was a more suited choice for me. Notice that i have not even considered Schimdt Cassegrain Type here beacuse the cheapest of them are unaffordably costly for me in India right now.

Celestron Powerseeker 70 EQ - The Telescope i chose, but then...

Now the search began for a telescope on ebay. Due to the limited budget and shipping and availability constraints i settled for a 'Celestron Powerseeker 70 EQ', price 7142/- INR. Free shipping. Yes it is a refractor, but you need to read the second sentence of this paragraph again. Yes, i had chosen and ordered my telescope, who new something else was in store for me. Find out in the next post.

1 comment:

  1. Nice post! This post is very useful.Thank you for sharing.You can get telescope, red dot sight, rifle scope and binocular etc from http://www.bosmaoptics.com/ with good quality and wholesale price.

    ReplyDelete