View Single Post
Old 12-12-2008, 03:51 PM
Registered User

Wavytone is offline
Join Date: Jul 2008
Location: Killara, Sydney
Posts: 4,147
Originally Posted by NCRAW View Post
So great for Lunar and planets?
The Orion ED102 f/7 is certainly better than I expected on moon and planets at high power. I used to think good refractors had to be f/12 - f/15 to perform properly and that is clearly no longer the case, thanks to much better glass types.

Originally I bought it for low power wide field casual observing (Vixen NLVW 30mm eyepiece) but I found to my pleasant surprise that with an 8mm its still tack sharp and with a 5mm the diffraction rings are barely discernable.

First quarter moon - you could spend hours exploring crater floors.

It will take 200X (3.5 mm) with no problems, and is better on Jupiter than my 180mm Maksutov (though I think that Mak has problems). Through this scope I'd swear the Jovian moons are distinctly non-stellar, though I know that is impossible with a 102mm aperture. The background sky is velvety black - no issue with scattered light, and the Airy disks are exactly what i expect of a well-corrected refractor. No spherical aberration, which means it was designed for imaging or use with a diagonal mirror - not a prism star diagonal.

If you want to get to 200X or more the real issue will be the quality of your eyepieces and keeping them clean; it means using a 3.5mm or less.

This scope deserves a couple of really good, sharp eyepieces with low scattered light, the contrast it gives is stunning.
Reply With Quote