Subject:
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Re: (not quite) Looking at Mars
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Newsgroups:
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lugnet.space
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Date:
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Sat, 16 Aug 2003 18:09:35 GMT
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Viewed:
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421 times
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"Tony Alexander" wrote:
> A few years ago I went to Target and bought a little telescope from • the toy
> section: a Discovery Channel telescope, 300 power, 50 mm; I forget the • actual
> manufacturer's name, but it was a real telescope company, and this was • their
> lower-end introductory version. It came with a 3x Barlow lens, a little
> right-angle doohickey, and 3 lenses: h20mm, h12.5mm, and f6 mm. And
> instructions, but it's been several years, so God only knows where those • went.
> Buying another isn't an option for me; I can barely afford to feed my Lego • hobby
> when I'm lucky.
Hi Tony,
Given that your scope is a 300x model, you have a 3x barlow, and your
smallest
eyepiece is 6mm, I think it's reasonable to deduce that your objective (the
big
lens in front) is a 50mm f/12 with a focal length of 600mm. To determine
the
magnification with any given eyepiece, just divide 600mm by the eyepiece
focal length. For your eyepieces we get:
20mm: 30 power
12.5mm: 48 power
6mm: 100 power
Just multiply the magnification by 3 when using the 3x barlow. BTW,
I don't recommend using the barlow for much (if anything), it's just
included to make the top magnification of your scope higher (sorta
like the 120x digital zoom they sell on camcorders nowadays).
For most viewing, the 20mm eyepiece will be your best friend because it
gives the widest and brightest view. Once you've located the object of
interest, switch to a higher magnification (mostly when looking at planets
or the moon). Just switch out the eyepiece gently. You probably have
to refocus given that yours is an introductory scope.
HTH,
Mark
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Message has 1 Reply:
 | | Re: (not quite) Looking at Mars
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| In lugnet.space, Mark Riley wrote: (Lots of great stuff!!) Mark, WOW!! Thank you very much for your kind thoughts! That really helps to understand how the lenses work, and how to view at the higher magnifications. I'm going out this evening to sight (...) (21 years ago, 16-Aug-03, to lugnet.space)
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Message is in Reply To:
| | (not quite) Looking at Mars
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| Greetings, fellow .Spacers! A few years ago I went to Target and bought a little telescope from the toy section: a Discovery Channel telescope, 300 power, 50 mm; I forget the actual manufacturer's name, but it was a real telescope company, and this (...) (21 years ago, 16-Aug-03, to lugnet.space)
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