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Author Topic: telescopes  (Read 2869 times)

Offline qazibasit

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telescopes
« on: 22/05/2005 17:09:35 »
any expert here who can guide me regarding telescopes i want to get one but dont know anything about its power and diopters  whatever you ppls say in physics language and how can i view the distant galaxies any idea.


 

Offline neilep

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Re: telescopes
« Reply #1 on: 22/05/2005 17:33:43 »
I've messed around with sky watching before and contrary to popular belief a good pair of binoculars will get you up and running and is usually the first piece of skywatching equipment to buy.

The best ones I have found are 7x50 and 10x50 models. The 7 and 10 indicate the magnification, and the 50 is the aperture, that's the diameter of of each front lens in millimeteres. It's worth mentioning though that the higher the power the more tricky it is to keep them still so a tripod will be a worthy investment too.

Regarding telescopes though...well, there are a plethora of choices and prices and there are at least three types of telescope, ones that use a mirror to collect the light (reflecting), ones that use a lens (refracting) and ones that use a combination (I can't remember their name). Don't think it's all about power though.....no, it's the aperture that is paramount here cos it's possible to change magnification by changing eyepieces. Depending on your budget , as a rule, reflectors provide much better aperture for the money than refractors and an economical 4.0 - 4.5 inch can serve you as a good starter scope, however, they do require maintenance and a small refractor( 2.4- 3.5 inch) is maintenance free and they also double up for day time use too.

So, give it some thought, seriously consider a really good pair of binoculars first....but, if you have a local store with a good choice then go there and chat, hopefully you'll get some good hands-on advice

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Offline gsmollin

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Re: telescopes
« Reply #2 on: 22/05/2005 23:25:53 »
Beside the binoculars, the best first scope is a six inch Newtonian reflector. Schmidt-Cassegrains, Maksutov-Cassegrains, and refractors are second choices, because they are expensive. Your first telescope will not be your last, so you should pick the best all around scope for planetary, deep-space objects, EASE OF USE, and price. The ease of use is actually the most important, because some 200 lb. monster will not get used very often. The objective must still be large enough to be useful, and six inches is the minimum. The price must be moderate, so you can get a different scope later when you know more about what you want out of astronomy. The focal length of the the scope should be between f-8 and f-4.5, the former if you already know you like planetary, and the latter if you already know you like extended nebula. If you are not sure, then f-8.

So, to recap, get an f-8, six-inch Newtonian reflector for your first telescope.
« Last Edit: 22/05/2005 23:29:06 by gsmollin »
 

Offline qazibasit

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Re: telescopes
« Reply #3 on: 23/05/2005 17:51:27 »
thanks both gsmollin and neliep for your guidance i will go and will get one but can you tell me for how much i will get these two things can i get it in 500 US$ or i need a more budget.
 

Offline gsmollin

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Re: telescopes
« Reply #4 on: 23/05/2005 19:43:25 »
I have no idea what you can buy in your own country. You should find out all these details from a local astronomy club. If they are like American astronomy clubs, the members are all a bunch of old-boys, and are hungry for new blood. If you fit that category (e.g. you are not an old-boy) you can get a lot of help pretty quickly. They may be able to get you a good used scope too. A lot of beginners outgrow their first scope and are willing to sell at pennies on the dollar, and you can try it out before you buy. Many clubs also have club scopes you can rent. Then there's the sky party, where you can walk around and look through dozens of scopes. You can also oogle the 7 inch Takahashi APO refractors, 10 inch Astro-Physics Maksutovs and 24 inch Schmidt-Cassegrains with Nagler eyepieces. But I digress.

Here's an American mail-order web site, for what its worth:
http://www.telescope.com/jump.jsp?itemID=0&itemType=HOME_PAGE

I will offer this caveat: A good telescope mount is never inexpensive. While you can buy decent optics for a few hundred dollars, the mounts are always a disappointment. Soon you will curse them, as they fail to work with the precision and smoothness you need at high magnification. For an inexpensive first scope, maybe a Dobsonian is the best bet. A Dobsonian is a Newtonian reflector with a short focal length and a very simple mount that you just push around with your hand. They are best at low magnification, looking at extended objects such as nebulae. Planetary viewing is really the domain of expensive, and precise instruments.
 

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Re: telescopes
« Reply #4 on: 23/05/2005 19:43:25 »

 

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