Hello, I'm currently in the middle of doing my astronomy GCSE (well, just starting really), and I need to do a peice of coursework. I decided that from the available options viewing the various lunar details (craters, hills etc) would be a rather fun and acheivable thing to do. But for that I need a telescope, and so I bought a telescope on ebay to the tune of £200 (it originally cost around £400). I am a complete novice in astronomy and these are the various specifications of this telescope:

Clear aperture= 150mm

Focal length = 750mm

Focal ratio f/5

Mirror thickness = 16mm

Thickness/diameter ratio 1:9.6

Surface Accuracy = 1/8

So with a 6.5 mm eyepeice it will have a magnification of around 115, and I'm wondering whether this telescope will be good enough for my purposes?

p.s: you're probably thinking 'woa, this guy doesn't have a chance of getting even a G in GCSE astronomy', I have only just started properly, and haven't done anything on observing celestial bodies yet (I probably should have waited a while before getting a telescope, but I thought the current telescope I bought was a fairly good deal, since it's around 1/2 the original price).

Cheers,
Zachary

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"Bessie Braddock to Churchill "Winston, your drunk!"
Churchill: "Bessie, you're ugly, and tomorrow morning I shall be sober""
the solar system

The numbers "look" good. What kind of mount? Also check the collimation (do the eyepiece, secondary and main mirror all line up properly?)

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Any day you wake up on "the right side of the dirt" is a good day.

T. Anderson

The eyepeice, secondary and main mirrors seem to line up properly, and it's mounted on an aluminium tripod.

__________________
"Bessie Braddock to Churchill "Winston, your drunk!"
Churchill: "Bessie, you're ugly, and tomorrow morning I shall be sober""
the solar system

Equatorial or alt-az?

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Any day you wake up on "the right side of the dirt" is a good day.

T. Anderson

um, what does that mean? #-o . It does say it's equatorial in the instruction manual though.

__________________
"Bessie Braddock to Churchill "Winston, your drunk!"
Churchill: "Bessie, you're ugly, and tomorrow morning I shall be sober""
the solar system

An alt-az (altitude-azimuth) mount has two axes, up-down (altitude) and left-right (azimuth. An equatorial mount also has two axes, but one of them is pointed toward the celestial pole (near Polaris). The other is parallel to the equator. With a properly aligned equatorial mount an object can be kept in the field of view by movement of one axis. If the scope has a clock drive, it will automatically follow the stars, so you don't have to keep moving the scope to follow the rotation of the Earth.

__________________
Any day you wake up on "the right side of the dirt" is a good day.

T. Anderson

Hmmm...6" Newt, on an EQ mount, F5, with a 1/8 wavelength accuracy mirror...not bad, not bad.

Manufacturer?

That F5 puts you right on the dividing line - it's adequate for both deep space and planetary work. Sounds like a decent photography scope, too.

Quality eyepieces will make the difference here.

Congratulations!

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I've looked at both the telescope and the instruction manual but I can't find a manufacterer. The name of the telescope is called Event Horizon, but I doubt that helps in determining who made it. I'm also wondering about the age of the telescope, because even though the box had never been opened the colour on the box looked terribly faded. The picture of the telescope looks green.

Also, I live in London and the light pollution is terrible, so how does that affect my chances of seeing deep space objects?

And I'm wondering how to maintain the eyepeices as well, because both eyepeices I have didn't come with any caps, so how do I prevent dust from getting on the eyepeice? And the instruction manual says I should always keep the telescope in it's box, but it took me 3 hours to assemble it! So would the telescope be useable a few years down the road if I just put the cap on the lens and put it indoors when I'm not using it?

__________________
"Bessie Braddock to Churchill "Winston, your drunk!"
Churchill: "Bessie, you're ugly, and tomorrow morning I shall be sober""
the solar system

Bad news folks

http://www.space-talk.com/ForumE/sho...p;pagenumber=1

Good news: There is an article in the Nov. issue of Sky & Telescope on a cheap method of making a "quasi-parabolic" mirror out of a spherical one for about $10 in parts, by flexing the mirror. In essence, you glue a flat head bolt to the back of the mirror and pull it into an approximation of the correct shape. The difference between a sphere and a parabola is only a few microns in depth, but it makes all the difference in the world in terms of image quality.

__________________
Any day you wake up on "the right side of the dirt" is a good day.

T. Anderson

Zachary, Good name. Liked it enough to give it to my youngest son.

I have an old Criterion 6" EQ mounted on an Orion EQ Deluxe tripod. My rather limited experience enhanced by asking questions of more seasoned viewers has taught me the following:
1. Collimation is crucial. http://zebu.uoregon.edu/~mbartels/kolli/kolli.html
2. Lenses are important. Buy the best you can get and still justify to yourself. Pay attention to eye relief.
3. Barlow lenses can replace the need for higher power lenses if you get a good one.
4. Protect lenses with cellophane and keep in a padded case. Foam rubber with cut-outs for the lenses placed in an old shoe box works.
5. No need to break down the assembled scope if you have an out of the way place to store it. Keep dust an insects out of the main tube by putting shower caps over the ends, or plastic secured with a rubber band. Focuser should have a dust cap on when not occupied by a lense. No dust cap? Sometimes a 35mm film cartridge or lid will fit. I actually was able to use an old milk jug lid. Cover entire scope by an old sheet.
6. You can buy filters to help compensate for light pollution. DO NOT try to view the sun without an objective filter (filter covering the big open end of the scope where light enters).
7. If you plan on viewing the moon for any length of time you may want a moon filter. Or, partially obstructing the objective aperture can block enough light to make viewing confortable.

Hope this helps. Accessorizing your new telescope can almost be as much fun as viewing.

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