Telescope Buying FAQs

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Q. Help, I’m a newbie, what telescope should I buy?

A. This would work a lot faster if you specify how deep your pocket runs. It is best to keep aside atleast Rs 20,000/- for a decent scope that will last a while. If you are buying one from abroad, say a US vendor, decent entry level scopes start from USD150 to USD 300

Q. Which scope is better? A reflector or a refractor?

A. Well, there is no right answer. There are however pros & cons of both. A reflector will cost you far less than a refractor for the same aperture. The refractors usually come in high F-ratios like f/9 to f/15 which makes them great for planet viewing. Reflectors on the other hand are good for DSOs where maximum light gathering ability is needed.

Q. I found a cheap telescope in a mall yesterday. Should I go for it?

A. If its sold in a mall, its probably a toy…Spend the money on something more useful

Q. This scope I saw had a 800x magnification, should I buy it?

A. Never EVER buy a scope if its sales pitch is its magnification. A telescopes absolute rating is its aperture..i.e tube diameter. Bigger diameter tubes can grab more light and will resolve more details in deep sky objects. However, most 6″ + dobs are pretty fast i.e have focal ratios of F/4 – F/7, which may not be suitable for imaging galaxies or small objects. If you are into imaging, you probably shouldn’t be on this page.

Q. Where can I buy a scope in India?

A. For a non comprehensive list based on an amateur search CLICK HERE

Q. What kind of scope is the best for me?

A. Traditionally, we recommend Dobsonian scopes for absolute nOObs but that shouldn’t keep you from diving into other optical/mount designs

Q. Is it okay to buy a scope with plastic lenses?

A. You’ve got to be kidding me! :-O

Q. What kind of scope is good for astrophotography?

A. Typically it is good to have telescope that has a small F-ratio. Most scopes around F/4 to F/6 are considered good for photography. The reason for this is that small f ratios give a wide field of view of the object, which is good from the point of view that the required exposure times are smaller. Secondly most DSOs like galaxies have pretty large angular spans. For example the Andromeda galaxy M31 is 178 x 63 arc min across. This is way bigger field than typical F/9 Newtonian designs.
Small F ratios are very popular in the amateur astronomer community

However this does not apply for photographing planets. To typically capture details on the planetary disc, a lot of magnification is required. For example, Jupiter at opposition typically has an angular width of 29 arc seconds (compare this to galaxies) Also taking into account that Jupiter is almost a -2.5 mag at opposition, we do have some light to play with. In this case F/9 – F/11 optics are useful.

According to the author’s experience, there is no 1 scope fits all. You need to know what you’d like to photograph before making a purchase decision

This section is continuously being expanded. If you are an experienced astronomer and would like to contribute to this page, please email Your help in building this resource will be appreciated

Since May 29th 2009

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