I have bought and sold the Televue 13mm Type 6 twice now, and each time have replaced it with a Meade 14mm UWA. Dont get me wrong, the 13mm Nagler Type 6 is a fantastic eyepiece. Very sharp on axis with very high contrast. There is significant field curvature at edge if you use it in the daytime. Not noticeable at night, although the Meade 14 UWA was sharper on edge. IMHO doesnt give that 3-D effect that I get on Nebula(Ring)with the 14mm UWA.