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Telescopes

Help with a telescope
Last post 01-01-2009 04:45 PM by chipdatajeffB. 10 replies.
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  • 01-01-2009 12:23 PM

    Help with a telescope

  • 01-01-2009 12:38 PM In reply to

    Re: Help with a telescope

    In my opinion, nope. You'd be better off with an Orion StarBlast.

    This eBay seller has long made a big deal in his ads about the color of his telescopes. They are extremely cheaply made imports. Some of his larger telescopes I've seen have simply fallen apart after a few night's use. I know two people who have had no luck returning them as defective.

    In the ones I've seen the optics are shoddy. One was totally uncollimatable. Another had severe spherical aberration, so it would collimate but gave horrible star images even so.

    This is also just my opinion, but you want to steer clear of eBay when shopping for a telescope. If you're looking for a "deal", shop Astromart instead. Or if you want to ensure you can return it if you don't like it, go to Orion. Their warranty and return policies are great, even for their clearance merchandise.

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    The universe is not only stranger than we imagine, it's stranger than we CAN imagine. --- JBS Haldane
  • 01-01-2009 12:43 PM In reply to

    Re: Help with a telescope

  • 01-01-2009 01:49 PM In reply to

    Re: Help with a telescope

    That one is similar, though the dealer is certainly more reputable.

    The mount, however, is wobbly.

    I also just realized you specified "deep space" and both these scopes suffer from a lack of aperture.

    I have watched many, many people get started in this hobby, expecting to be able to "see" galaxies and nebulae, only to be disappointed by lack of aperture.

    We must define what we mean by "see":

    1. "Notice" something in an eyepiece view that is different from a star or planet, but not obviously a galaxy or nebula.
    2. See enough detail in an object's eyepiece view to realize it's a spiral galaxy and not a nebula, or that it's a particular type of nebula.

    If what you want to do is (1) then a 4.5" aperture will do. A 6" aperture will be much better, but still won't generally get you to (2).

    If what you want to do is (2), then a 6" refractor (clear aperture) will do for many targets, an 8" will be better, and a 10" will be better still.

    All that being said, it is true that all the Messier objects can be identified using a 3" refractor. But "identified" and "seen" are not the same thing (see above).

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    The universe is not only stranger than we imagine, it's stranger than we CAN imagine. --- JBS Haldane
  • 01-01-2009 02:00 PM In reply to

    Re: Help with a telescope

    The main thing  I want to do is see As alot of detail on the planets in our solar system. I also like looking at clusters and looking at nebulas and galaxys. Will this telescope allow this?

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    The Naked Eye
  • 01-01-2009 02:14 PM In reply to

    Re: Help with a telescope

    Your best views of planetary detail require both aperture and focal length. You need enough aperture to provide a bright view at magnifications above 150X, which generally means a focal length of at least 900mm.

    A 4.5" reflector can do this, but just. You still want a good focal length.

    I have seen very good views of Saturn and Jupiter in the Orion XT6 reflector. It provides enough light for a decent view at 200X, so it's good for planets. A 6" refractor would be better (since there is more contrast and light due to the clear aperture), but its disadvantage would be that it's very big, requiring a solid mount, and more expensive.

    A 6" reflector is on the low end of "usable" for galaxies and other DSOs. So, at minimum, I'd recommend a 6" reflector.

    An 8" would be better and a 10" better still.

    If more than 75% of your observing would be the Moon and planets, then a good 4" refractor (something like the Celestron 102, minimum) would be a good choice. It will still put in some galaxies and nebulae and would do a good job on the planets.

    On a typical night, the instability of our atmosphere will limit you to magnifications of from between 250X and 300X, which is were really detailed planetary views normally begin. But even on an average nights there will be moments of steady seeing that will make it worth your while.

    So, on balance, I'd suggest either a 6" (150mm) reflector or a 4" (102mm) refractor with a minimum of 900mm to 1,000mm of focal length.

    For eyepieces:

    • Moon: Just about any focal length is fun, but a 15mm and a 10mm would be great. Nothing shorter than a 4mm at the above focal lengths, however.
    • Planets: Either or both of a 5mm and an 8mm for good detail at the apertures above.
    • Galaxies: 25mm or 10mm would be good at the above apertures and focal lengths.

    Notice that if you have a 25mm and a 15mm eyepiece plus a 2X barlow you can pretty much cover the above range, except at the extremes.

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    The universe is not only stranger than we imagine, it's stranger than we CAN imagine. --- JBS Haldane
  • 01-01-2009 02:19 PM In reply to

    Re: Help with a telescope

    thanks much. you have been a huge help. would you recommend the meade I showed you or this.

     

    http://www.telescopes.com/telescopes/reflecting-telescopes/celestronpowerseeker127eqtelescope.cfm

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    The Naked Eye
  • 01-01-2009 02:23 PM In reply to

    Re: Help with a telescope

  • 01-01-2009 04:17 PM In reply to

    Re: Help with a telescope

    I would agree with Jeff completely & recommend the Orion Star Blast . In the price range your looking at , it is the best thing to do . All of the equatorial mounts on the scopes in this low end price range are going to be so rickety , that the frustration involved in trying to gain a steady image will spoil any amount of fun that this hobby has to offer . Orion puts the money into the optics on the Star Blast & it has rave reviews . The half Dob mount that it sports is much more stable than these low end E.Q. mounts . The best telescope in the world is useless if your mount won't sit still . The mount is just as important as the optics .

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  • 01-01-2009 04:25 PM In reply to

    Re: Help with a telescope

    thanks for the recommendation, however I can't seem too find a "starblast"

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    The Naked Eye
  • 01-01-2009 04:45 PM In reply to

    Re: Help with a telescope

    Orion 4.5":

    • StarBlast tabletop model is here.
    • Standard dobsonian model is here.

    Orion  6":

    • StarBlast tabletop model is here.
    • Standard dobsonian (XT6) model is here.

     

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    The universe is not only stranger than we imagine, it's stranger than we CAN imagine. --- JBS Haldane
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