[off topic] - Buying a telescope I need advise

[Edil]

Hi!!!

I live in a condo so space is small. I have a budget of $300. It is possible to buy a potent telescope but with a small lenght?

I realle need your advice I have no idea of what things to check before buying a telescope?

[Edil]

Ok I did a little research and i think that I will raise my budget to $500. It is possible to get a Schmidt-Cassegrain or Maksutov-Cassegrain telescope for $500. I saw those and they are very small, exactly what i was looking for. If I'm gonna buy that king of telescope what things do i have to check. I'm planning to buy this over the internet.

[Sum0]

OK, i'll try to help...

Buy some binoculars if you haven't got any and use them for a while - it's generally a good idea to get some experience with them before you go spending hundreds on a telescope.
Get some books on choosing and using a telescope - they can go into more depth than I can here.

I'm not sure about prices, but if you have the money get a 6 inch reflector or Schimidt-Cassegrain. If you really can spare the money get a computer-controlled telescope, but this isn't essential, and I wouldn't recommend skimping on the telescope itself just so you can find things quicker.
If you can't afford 6 inch then 4.5inch is a good alternative. If you want to look at galaxies and nebulae a short focal length (f.4 or below, I think) is best - for planets, something above f.8 is best. If you're not sure, then something in the middle will be fine.
Then there's the make of telescope - anything like Orion or Meade is fine. Do a search for the maker on the net or newsgroups to see if they have any problems.

OK, that's my 2 pence, anyone else?

[ANDREA]

OK, i'll try to help...
...............................
OK, that's my 2 pence, anyone else?

I agree with Sum0 on choosing a 6 inch or a 4.5 inch telescope, but I would like to add something, being an amateur astronomer from 52 years (I'm 58 years old) . The most important thing is to know from where he'll observe. If he will do it from his combo, I suppose that there will be a lot of light pollution, and in this case the possibility to see diffuse objects like galaxies and nebulas is at least problematic, if not impossible . In this case it's preferable to have a long focus telescope, and observe luminous objects, mainly Moon and planets (the long focus is needed in order to obtain big magnification). Many small (diameter between 60-75 mm) refractor scopes have little prices, and could be a good solution in this case. If he'll bring his telescope far away from city lights, the choose must be on the instrument diameter, aka the biggest the best (at same quality conditions) .
This because to observe dim objects the main factor is the capability to collect light, so big lens or mirror diameter.
In my life I used about everything was available on the astronomical market, from military scrap to gorgeous instruments, but the best ones in my opinion are the modern apochromatic refractors, that anyhow have a very big defect: high price versus small diameter , so I prefer the mixed version, the Schmidt-Cassegrain like Meade, Celestron and Orion, that have a mirror-lens system giving normally a long focus (most of them are f/10, i.e. the focal length is diameter multiplied by 10, so a 6.0 inch is 60 inch focal length, and so on), very good for planetary observations; but with a small additional lens system (whose name is focal reducer) they can be modified to f/6.3, that means they are about 1.5 times more luminous that at f/10, allowing the sight of bigger fields at lower magnification.
As final attempt to give some help, try on the used market, that for such objects is very diffuse, mostly in USA. For this I can suggest a visit to Astromart or any other telescope auctions web site.
Whatever will be your decision, welcome among the sky looking people!

Andrea
157 Frasso Sabino Observatory
RHP SpaceGuard Team
http://www.ara-frasso-sabino.org/andrea_celestia.htm

[timcrews]

I second the recommendation to look into used telescopes. Unless abused, there is hardly anything that makes a telescope "wear out". Also, they hold their value pretty well, so there is a good chance that if your astronomy enthusiasm wears out (an unfortunately common occurrence, maybe because we are spoiled by crystal clear and bright images such as we see from Celestia or the Hubble Space telescope), you will still be able to sell it for nearly what you paid for it. That is, IF you bought it used in the first place. In fact, that's the reason there are so many hardly-used telescopes on e-bay. If you find a well-rated seller, I am pretty convinced that you will have a good experience.

Or if you head to your local telescope shop, you will also find used telescopes. They will be more expensive than the e-bay deals, less expensive than new, but at least you can count on the support that would come from your telescope shop, which after all has a reputation to protect.

I also second the observation that if you live in a light-polluted area, you are going to have trouble seeing much other than the moon, planets, the Orion Nebula, and star clusters. I live in the extreme southeast reaches of the Phoenix metro area, thirty miles from the center of Phoenix, and still have only had one or two experiences where I saw anything other than the above list. (With a Celestron C8.) But I still love my telescope.

Tim Crews

[Guest]

thanks for all your advice!!!

Hey I saw the Takahashi FCL-90 [sky-90] fluorite apochromat refractor telescope!!!! wow!!! the only problem is that I said 500 not 5000 LOL!


It seems that even when smaller they are more expensive.

Andrea you just said everything that I want. My apartment is in a 15 floor and I want a telescope with a short lenght not only to watch from my balcony but also I want something that I can move easily trough doors and the elevator when I go out.

I want to buy over the Internet, period. I don't want to get into details but buying in a local store is not an option, they always charge 3 times what it really cost.

That Takahashi really looks good!

[John Van Vliet]

check the local lyberary for astronomy clubs ,or online,there showld be one in your area . great deals can be found through club members.

[ElPelado]

i also wanted to buy a teelscope. i saw one of the firm Optisan. it has 114 mm of diameter, and a f.8. what do you think about it?
it cost $500

now i am thinking that a binocular is best for starting.
i saw some bushbell models:
7x35
10x50
16x50
12x50

can some one of this help me to see the sky?

[praesepe]

i also wanted to buy a teelscope. i saw one of the firm Optisan. it has 114 mm of diameter, and a f.8. what do you think about it?
it cost $500

now i am thinking that a binocular is best for starting.
i saw some bushbell models:
7x35
10x50
16x50
12x50

can some one of this help me to see the sky?

It depends on how better do you want to see and what usage are you going to do. I've got a Newtonian 114 mm f7.8 and 1000 mm focal distance and well, for planets is ok, unless the farthest planets like Neptune, Uranus and Pluto, which are simple feeble dots. For closer ones you can get some nice views if you use an eyepiece that provides the maximum magnification (for a Newtonian 114 it is at 228X). I've got some nice photographs of the Moon, Saturn and Jupiter (which I use to compare to check Celestia's accuracy) through the eyepiece projection method on a 2 megapix CCD camera. On Nebulas things get so difficult, not with the bright ones like M42 but hard when you are trying to locate small or low brighted ones.

Now I'm looking for a Schmitd-Cassegrain to get better results.

[ElPelado]

can you post any of the pictures that you took with it?

[praesepe]

Sure!

Here are some of them

A closeup, at 200X, Mare Tranquilitatis, Mare Fecunditatis and Mare Nectaris, Montes Apeninus can be seen at the bottom. Taken on 9-3-2003 22:32 (GMT+1).


A closeup, at 228X of crater Copernicus, Taken on 9-3-2003 22:03 (GMT+1)


Another closeup at 228X, taken on 10-5-2003 21:57 (GMT+1)


Another closeup at 228X, taken on 10-5-2003 21:57 (GMT+1)


Saturn at maximum magnification, 26-4-2003 22:04 (GMT+1), bad seeing and some termical noise.


P.S. Note that all the pictures are not taken at the same resolution. All were taken using a 20mm Plossl eyepiece and Barlow 2X attached to a homemade focal enlarger

[ElPelado]

those were taken with your newtonian??
do you have jupiter pics?

[Sum0]

They're good photos, yes, but they can't compare to Celestia...

[praesepe]

Yes, all were taken with my Newtonian, I haven't got any other telescope, at least for now

I've created this comparison image of my photograph and Celestia, take a look!:

[praesepe]

They're good photos, yes, but they can't compare to Celestia...

Sure, as long as my telescope is not as powerful as Celestia is

[ElPelado]

jupiter looks very good!
which magnification did you use in the jupiter picture.

[praesepe]

jupiter looks very good!
which magnification did you use in the jupiter picture.

Thanks! I used Barlow 2x+20 mm Plossl eyepiece+Homemade focal enlarger+2x digital zoom of the CCD camera, resulting in a virtual 228*2 zoom, 456X

[Apollo7]

I too am looking to buy a "first telescope" For nearly twenty years I've studied astronomy at an amature level, including affiliated fields like Chemistry and Physics. However, up until very very recently I've never really cared about observational astronomy. Afterall looking at Naos tells me little, if anything, about how it works on the inside. Anyway, I am truly clueless when it comes to scopes/optics, and I'm weary of buying anything as I haven't got the knowledge to know what is good and what isn't.

I've got a pair of 8x40 Simmon's Binocs which work very well and my knowledge of the sky has improved. Hard to believe anyone can study astro for so many years and not really observe the sky eh? Anyway I'm safely tucked away in Houston Texas, where I live the light polution is moderate, and fortunately not overbearing. I have lived in Seaside California for sometime as well and the seeing there was even better, but anyway back to my point.

I keep hearing that a 6inch reflector is a good place to start, I'm not looking for anything extravagant myself, just something to get me started. Well any ideas or feedback would be appreciated. Cheers.

[t00fri]

Well I can look back to vast experience with amateur astronomy since
childhood. Moreover, I did sophisticated measurements of Schmidt-Corrector
plates with laser interferometry, vast amounts of computer simulations of
complex optical systems and also ground a couple of 8 inch mirrors
myself. I also own various instruments including a Celestron 8 Schmidt
Cassegrain system. I have observed through a large range of
instruments ranging from small refractors to 14 inch Zeiss refractors,
from an excellent 4 inch Newtonian to 1 meter reflectors.

So I guess I can give 'first hand' advice to people who are really
interested in quality astronomical instruments.

Here are some very elementary general comments:

1) There is no perfect allround instrument! Think first what you want
to observe mostly (planets and other contrast-sensitive objects or
rather deep sky things that are calling mainly for light gathering power!)
Fold in your local seeing conditions!!!

2) I would never advice to buy an expensive refractor as a first
instrument. You will be shocked about the price and almost
certainly spend too little money on a too small instrument!

3) The main priority should be on /optical quality/, not technical
gimmics. An excellent 4-8 inch reflector can be much more rewarding
than a too cheap refractor. When comparing prices you should
remember that the price you pay refers to the /spread/ in quality,
mostly! A 6 inch Zeiss Maksutov tube assembly would be perhaps
10000 $/Euro while you get a complete Meade 12 inch LX200GPS for only $3000!
When you buy 5 such Zeiss instruments, you will find that they are
of almost indistinguishable quality, however... Not so with Meade or
Celestron... (I know what I am talking about;-)). If you have a
chance of skytesting these cheap mass produced instruments before
buying, this may save you lots of money, of course.

4) My recommendations would always be for a /mirror system/ of not too
short forcal ratio (aberrations!) that has a comparatively small
central obtruction (< 30%). Note that instruments >10inch get /very
bulky/ and hence are largely for stationary use. This may be a big
disadvantage!


...and so on....

Bye Fridger

[Apollo7]

I don't know how other people are but I can say with great confidance that my interest is NOT in observing planets and the moon. Yes I'm sure this would be a great bit of fun, but its not really where my interest is. From where I sit I want to be observing stars, singles, multiples, clusters, binaries, variables. My whole interest is to get a good look at the different stars in the sky and the systems they inhabit.

I supose by association I'd also like to see some Deep Sky objects.

In any event, planets are not my bag, so I supose that is something to consider from what You've said.