Telescope Questions

General physics and astronomy discussions not directly related to Celestia
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Darkmiss
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Telescope Questions

Post #1by Darkmiss » 19.01.2004, 22:31

Hello all
I have a few questions for telescope users, if you will.

i have been lokking at a few telescopes to buy
but never having used one, (apart froma a cheap tiny thing as a child)
Im not really sure what im looking for.

I have found one i like the look of here :arrow: http://hardinoptical.com/meadeetx90ec.html

To the questions:
1: is this out of my depth, or would i quickly grow out of it :?:
2: is this a good price, or too expensive :?:
3: are there things that this wouldnt do that other home telescopes can :?:

4: anything else i should know about it :?:

Sorry if these questions are strange, but as i said im very new to this,
and would like to experience the real thing, some time soon :D


I would like as many opinions on this as posible, if you would.
no matter how different. so if you have any info for me, please step up and help me on the right track.
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selden
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Post #2by selden » 20.01.2004, 00:08

Paul,

I'll repeat what I suggested in another thread: attend some of the local amateur astronomy club meetings and get some personal opinions. Most amateur observers are delighted to help, including letting you look through their 'scopes.

You also should consider used equipment. It'll be a lot cheaper than new. Of course, that assumes you'll be able to get someone experienced to help evaluate it in person. (see above) You may find that the pain of having to schedule your viewing time at the whims of the weather and the phase of the moon (it's really bright) just doesn't work for you.

My personal opinion is that something like that would indeed be appropriate for a cloudy, light polluted viewing location like London. Questar telescopes have a very similar design (although they cost a lot more) and people get great pictures with them. I have no personal experience with either, though, so take this comment for what it's worth.
Selden

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Post #3by Guest » 20.01.2004, 02:46

Hi Paul,

I went through the same thing about 4 months ago. In my case the nearest astronomy club is quite a distance so I had no chice but to ask advice but in the end go it alone.

I settled on a 102 Mak by skywatcher on an eq2 mount. Since the optical assembly is similar I thought I'd reply with my experiences.

1) Opticaly the scope gives good images even at high gain on planets and the moon.

2) It makes an excellent spotting scope also

3) It is a totaly hopeless scope to look at deep sky objects, not enough appature and a very narrow field of view.

If you have any intention on ever looking at galaxies, resolving globular clusters or looking at nebula's then you will eventually want to buy a bigger scope.

I at present am looking to do two things:

1) buy a GOOD pair of binoculars

2) buy a newtonian based telescope of a much larger appature.

To give you an idea for comparison, the scope I have now is slightly larger than the etx90 (by 12mm) and I observe from an rural area with no smog or light pollution. The best I can get out of deep sky objects is a faint smudge.

The old saying "there's no substitute for size" really does apply to telescopes.

Good luck.

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Post #4by tony873004 » 20.01.2004, 03:42

I own that telescope (ETX-90), and also a Celestron. A few months ago around the time of Mars' opposition, Costco had a large supply of Celestron GT114 telescopes for only $200. Check it out at your local Costco and see if they still have them. Then, a week after I bought it, it went on sale for $160. I went back and got my $40 refund. I love this telescope. It is computer controlled, comes WITH the tripod, and is very easy to use.

The Meade cost me nearly $1000 about 4 or 5 years ago without a tripod. They've come down in price since then. Although the Meade has higher quality optics, and comes with a higher quality eyepiece, I still prefer the Celestron. For one, its mirror is 114mm compared to 90. Also, about a year after owning the Meade, it broke. The knob that you loosen so you can manually pivot the telescope up and down broke. I couldn't move the scope up or down manually or with the motor. Since I'm good at fixing stuff, I opened the telescope and fixed it so that it at least worked with the motor. Also, I don't know if they've improved the motors since I bought my Meade, but the Celestron has much better motors. With the Meade, if I wanted to move from one side of the moon to the other, I'd press the arrow button, wait about 10 seconds for the motor lag to disappear, then watched it move. If I overshot my target, I'd have to put up with the motor lag (I believe they call it something like backlash) again in the other direction. The Celestron has almost no motor lag. And it is much more accurate than the Meade. After carefully aligning the scope, I was able to tell it to goto Mars and after slewing across half the sky to get there, it was able to center it in the high-power eyepiece.

I don't know if Meade has improved their product since I bought mine. I imagine they have. But check out Costo before you buy anything.

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Post #5by Kendrix » 20.01.2004, 12:05

The ETX-90 has a focal ratio of 13.8 which definitly makes it for planet observations...

If you want to watch deep space objects you should by a Telescope with a ratio between 5 and 7

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Post #6by Darkmiss » 20.01.2004, 22:32

Thank you all.
This is the kind of info i was looking for
The "been there, done that" type of info. :)

I will be doing a search and review of the Celestron GT114, soon

And thanks Selden i did look into the courses and astronomy groups.
but there isnt any in my area at all.
And travel around london at the moment is real slow :evil:
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Post #7by Darkmiss » 21.01.2004, 18:44

well after more investigations and a check on the funds
Ill not be able to get the Meade ETX 90AT as it is just too expensive for me.

Instead i will be getting the Meade ETX 70, which by what i read is a great first telescope, for a good few years, then maybe ill upgrade later.

This will cost me ?299:00

Now im going to do some reading up on extra eye peice lenses
for different jobs, to get the most out of this telescope :)

i should have this in just over a week :D
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Post #8by Darkmiss » 23.01.2004, 18:56

Well after a shuffle of my finances, and a small loan on top.
I can now get the Meade ETX 90 AT
http://www.meade.com/catalog/etx/etx_mak.html

Ill be taking a trip to Telescope house in central London tomorrow morning.
and im getting very excited about it too :D

this will be my first real Telescope.

If anyone has any Top Tips for me of any kind let me know
:D
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Post #9by Darkmiss » 25.01.2004, 17:49

Well I got it.... :D and its good..... :D

I got the Meade ETX90AT with a 2x Barlow lens.



:) :|
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Post #10by tony873004 » 26.01.2004, 07:54

You'll have fun with it. I just dusted mine off. I got a new Canon Digital Rebel, and I want to connect it to my ETX-90 through the camera port. Gotta go buy the adapter tommorow. The Canon took some pretty nice star pictures last night just by itself without a telescope, but I can't wait to get it on a motorized platform.

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Post #11by Darkmiss » 28.01.2004, 20:16

Hello Tony
Well actually i got a good bargain from the shop I bought my ETX from.

The shop keeper threw in a free soft dew sheild,(?9.99) and a free Meade digital camera addon, (?89.99) and knocked ?5 off the price of my 2x Barlow lens 8O
Totaling a ?105 of extras and discounts :D

The telescope also came with the deluxe field tripod and the Autostar tracker.

I can wait to use it, I've only just finished fiddling with the autostar.
next i need to zero in the view finder.

But in a couple of months i'm off up north to Norfolk away from the city lights for a weekend, then ill put it through it paces.

Tony, what sort of things can i expect to be able to see with this scope.
could you post some of your best pictures, with a discription of the lens size and stuff ? :)
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Post #12by tony873004 » 29.01.2004, 19:33

I haven't taken any astro photos with my ETX-90. But I just got the adapter to attach my Canon Digital Rebel to the photoport on the back of the telescope. I just need to wait for the clouds to go away. But visually, here's what you can expect from each planet:

Mercury: with a high power eyepiece you can see its phases but you really have to look hard.

Venus: Now is a good time to look. Its phases are very obvious. By the way, get a solar filter for your telescope. On July 8th, Venus will transit the face of the sun for the first time since the 1800s. And England is the perfect place to watch (weather permitting). And your telescope is the perfect tool to observe this. Practice finding the Sun in advance. (After you have your solar filter and have covered the finderscope of course). For liability reasons, it's not included as one of the GOTO items because you can blind youself.

Earth: It makes a great terrestial telescope too because it doesn't invert the image.

Moon: Awesome.

Mars: Usually rather small and hard to see any detail. During August's opposition, Mars showed some surface markings and polar caps. At first glance, it just looked like a red disk with no features, but after staring at it for a minute, your eye begins to see shapes. At first I wondered if I was imagining them, but after staring for another minute it was obvious that they were real. Don't be discouraged that you missed the opposition. Even though this was the best opposition in over 60,000 years, there will be pleanty more in your lifetime that are almost just as good. Here's a computer sketch of what I saw:
Image

Jupiter: Very impressive. Huge. You can see its 4 moons, and under a clear dark sky, you can see the bands in Jupiter's clouds.

Saturn: Very impressive. You can see the rings, the gap in the rings, and it's large moon, Titan.

Uranus: I've heard that you can see it as a disk in scopes this small, but it never looked like anything more than a point of light to me. The only way I could distinguish it from the background stars was by looking the next night and noticing that it had moved.

Nepture: Same as Uranus, but dimmer.

Pluto: not visible.

The most impressive deep sky objects will be the Andromeda galaxy and the Pleadies star cluster.

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Post #13by Darkmiss » 30.01.2004, 01:51

Thank you Tony
I have only just got this scope, but hopfully ive got a long time to see things and get used to using it.

Jupiter and Saturn are the ones i really want to view
and your discription is very encouraging.

BUT: Mt garden is 10 foot by 15 foot
buildings bot sides of me, and behind my garden is a row of 40ft tall conifers. 8O
So i have a small square section of sky above me to view :(

So ill have to take it out to see anything.
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