Michael & Kim, Thanks for taking the time to respond. I understand about exit pupils and the math behind focal lengths and such, but what I don't understand are the relative advantages of the various eyepiece designs on the market. Nagler vs. Plossl, that sort of thing. I agree that only a few eyepieces are needed. I've done more star parties than I can count with just one 17 mm Plossl and one 40 mm Plossl. Adding the 30 mm Ultrascopic was (pardon the pun) a real eye-opener. Naglers are impressively wide-angle, pricey, and heavy. Is there anything else that performs almost as well but doesn't cost a fortune? If not, then I just want to know that. Plossls are light, small, and cheap. What's intermediate between these and a high-end Nagler or Radian? Is there such a critter? Is an Orion Lanthanum an acceptable substitute for a Nagler, or will nothing less than the real McCoy suffice? I appreciate your opinions & recommendations. Seth