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Old 18-01-2008, 08:51 PM
ausastronomer (John Bambury)
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Join Date: Mar 2005
Location: Shoalhaven Heads, NSW
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Quote:
Originally Posted by mbaddah View Post
Would it not be better choice to go for the powermate rather than the barlow? Thankyou.
I don't think so for a couple of reasons. With those eyepieces you only need a 1.25" barlow as the 26mm nag barlowed = 13mm Ethos. Therefore I figure you just barlow the two 1.25" eyepieces. Its not a huge scope so no point adding the weight of a 2" barlow to only barlow 1.25" eyepieces. Moving forward from there, the 1.25" powermate is 2.5X compared to the barlow at 2X. With the 13mm Ethos and the 10mm Pentax XW I think you will get more use out of 2X amplification than you will from 2.5X amplification. In terms of optical performance, the powermate seems to disappear a bit better, but if anything the standard 2X televue barlow is slightly sharper than the powermate. Overall optically they are very close indeed. The barlow is a good bit cheaper for optical equality and more usefullness in your situation IMO.

Cheers,
John B
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