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Diego
super member
Reged: 07/29/03
Posts: 179
Loc: Argentina South America
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Hello Gang,
I am enjoying my stay in the US after 14 years of living in Argentina.
I am not going back without astronomy hardware.
I have already purchased Ober. 20x90 binos, and now need some e.p.
My pre selection are Orion HightLight Plossl. They are Fully Multi coated.
My 6" scope has a f.l. of 975mm.
I usually observe DSO but also like the planets.
I'm not sure about the correct magnification though...
a 17mm and a 10mm seems right yielding 57 & 98X, but should
I go any higher in mag?
I am also buying Orions apo 2x barlow.
Thanks
Diego
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Diego
Celestron 80 mm f11.4
Oberwerk 20x90
6" f7.8 Reflector
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matt
Vendor (Scopemania)
Reged: 07/28/03
Posts: 10022
Loc: Chaville, France
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Oh, I do the same when I go to the US of A, Diego. Any reasonable scope (and I guess yours is one) can go up to 200x power. Maybe you could take one of Orion's or Celestron's low-priced, long eye-relief eyepieces for high power views.
Personally I don't like barlows much, I'd rather purchase 2 eyepieces than a Barlow.
That makes 4 eyepieces to chose. I'd take eyepieces to obtain a range from 200x (highest 'almost everyday use' power) to 30x (lowest power with a 5mm exit pupil, which will provide more than 1.5° foc, enough to frame the bowl of the Pleiades in one view). So in between i'd fit
(by increments of the third root of 200/30 (of course  )) 57x and 108x.
that's a 32mm, a 17mm, a 9mm and a 5mm...
Hmm... maybe I'd add an X factor and make it 25, 15, 8 and 5, especially as you already have big binoculars so don't need extra wide fields on the scope.
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Matt
CI700 mount with various scopes on top.
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NDonahoe
super member
Reged: 12/16/03
Posts: 155
Loc: Knoxville, TN
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Hey Diego,
I like your choices. Especially when you consider the prices. I, personally, would keep those two ep's and the barlow and add narrow band nebula filter (if you don't already have one). I can not even begin to tell of all of the wonderful things you can do with this. On the subject of mag, I think that you have nailed it. I have mag. ranging from 40x up to 400x, but when I look at planets my two most common mags. are 142x and 215x. I almost never use anything more than that.
Also, The Orion ED-2's are good for DSO and have nice eye relief, but they don't have the contrast or the sharpness of the Plössl's. Personally, If you ware glasses I would go with the ED-2's other wise I would stay with the Highlights. They will provide sharper higher contrast views.
-Clear Skies,
Nate
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"The heavens call to you, and circle around you, displaying to you their eternal splendors."
-Dante
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Diego
super member
Reged: 07/29/03
Posts: 179
Loc: Argentina South America
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Thanks for the replies. My skies are pretty clear, but I don't know what to expect with the atmospheric conditions.
With the 80mm Celestron, I tried 140x on Mars with a barrowed ep and all I saw was a red blur (I didn't have the 6" yet).
I'm including a nebula filter also. The barlow sort of doubles the number of ep. I just don't want to spend money on higher power I might not use.
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Diego
Celestron 80 mm f11.4
Oberwerk 20x90
6" f7.8 Reflector
Edited by Diego (01/26/04 05:33 PM)
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