Everything About Telescopes

Discussion in 'Astronomy, Exobiology, & Cosmology' started by Tristan, May 10, 2003.

  1. Klitwo Registered Member

    Messages:
    80
    I personally like the Chinese 150mm F/8 refractors like the Skywatcher, Synta and the Antares models, especially for lunar and planetary work. They are great on globulars too. Check out the link below. You may have to register for the Yahoo Chinese Refractor discussion group first inorder to view it. A good source for Chinese refractor telescopes and astromomy.

    http://tech.ph.groups.yahoo.com/group/Chinese_Refractor/photos
     
    Last edited: Jul 20, 2007
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  3. kaduseus melencolia I Registered Senior Member

    Messages:
    213
    Serious question about telescope optics.
    I don't know the correct terms so i'll try to explain the question.

    The reflector telescope uses a parabolic curve to reflect near parallel rays of light through the focal point. If you draw the curve x^2, the mirror uses a portion of the curve below the focal point, the 'dish' part of the curve. The eyepiece, as i understand it, uses glass or quartz lens to return the light to near parallel lines in a condensed form.

    The question is, is it possible to use the upper portion of the curve to form a 'chalice' that reflects the light back to near parallel rays of light, as a replacement for the eyepiece?

    I know an israeli chap uses a 'chalice' lens on a solar collector, i just wonderered if it had been applied to telescopes?

    Thanks,
    sorry if i completely misunderstood optics.
     
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  5. sreeja Registered Member

    Messages:
    13
    What type of telescope must be used frequently.
     
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  7. Havasu Astronomer Registered Member

    Messages:
    1
    Regarding books for Starting Astronomy

    I have used the Left Turn at Orion text for about a year it is very helpful also. We just got a 12" Meade F/10 RC with Ultra High Transmissivity Coatings. This Christmas we got the SBIG 4Mp Camera for the Scope. We will be getting it in a couple of months. I think that one of the reasons that I had so much trouble with the finder scope is that the image is upside down and backward in a lot of cases. It makes tracking a single image sort of a brain game. I have also found at COSTCO a very large and lovely text in the form of a Coffee Table Book called "ASTRONOMICA". This text has a very elegent yet simple set of diagrams that provide a month by month view of constellations, Nebulea, and DSO's, that we have used for hunting and imaging purposes. I hope this helps. Good luck with the Hobby. I will be interested in your thoughts.
     
  8. elte Valued Senior Member

    Messages:
    1,253
    i thought about a way to make a large objective lens. Evenly stretch plastic across a circular opening. cover it with some transparent solution which will harden. It should be possible to make a lens up to a couple feet in diameter, or wider, this way. For a larger lens, place an additional rim around the perimeter to allow the fluid to be poured extra thick.
     
  9. nixxy Registered Member

    Messages:
    4
    Star Question

    Hope you don't mind me asking a non-telescopt ytpe question, but I figured the guys with the scopes would know.
    This evening at about 9 PM pst from CA. I observed a star on the eastern horizon theat was twinkling with very prononced colors of blue, red, off white, and regular star-like brightness.
    I'm 51 and have never seen anything like it. Am I over the hill, or can someone explain what I seeing?
     
  10. Pete It's not rocket surgery Moderator

    Messages:
    10,166
    Hi nixy,
    Bright stars low on the horizon sometimes give a lovely show of twinkling in different colors. I'm fuzzy on the details, but it's apparently due to the starlight passing through lots of atmosphere of different temperatures.

    Given the time and place, I'd guess at Spica or Arcturus.
     

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