[astro_south (Andrew)]

Wayne

I have an 8mm Radian and it is my primary high power eyepiece in my dob (~238x). It also Barlows up quite nicely and gave me incredible views of Saturn at ~476x (Shory Plus 2x barlow) a while ago. I also own a 9mm 66 degree Expanse clone which I rate highly, but it just isn't in the league of the Radian. I have had no issue with kidney beaning or blackout while using this eyepiece, and it is very easy to position the eye. At this high power the field is nearly aberration free with only a slight bit of chromatic aberration at the very edge (and I mean edge) of the field as a bright star enters or exists the field. Your lx90 will track so this won't be an issue (and isn't an issue for me in my dob as it is very fleeting).

The pentax's are another good option, and I doubt you would loose much (if anything) in on-axis performance from what I have read. Some of the longer focal length Pentax eyepieces (14mm +) can show field curvature and abberations (seagulls) in fast scopes, but again this isn't an issue for you. If you purchase the 8mm Radian though, you won't be sorry. At 250x it will be used a lot - planets, multiple stars, Homunculus nebula, planetary nebula, and globs.

It was also my first TV eyepiece and I got it 2nd hand off Astromart. Since then I have also gotten a 13mmT6 Nagler and a 19mm Panoptic. These three form my primary eyepieces and one day I hope to add a 35mm Panoptic to this lineup.


Hope these ramblings help....

Andrew