University Optics 12mm König wide field 1.25" eyepiece
The König eyepiece has a concave-convex positive doublet and a plano-convex singlet. The strongly convex surfaces of the doublet and singlet face and (nearly) touch each other. The doublet has its concave surface facing the light source and the singlet has its almost flat (slightly convex) surface facing the eye. It was designed in 1915 by German optician Albert König (1871?1946) as a simplified Abbe. The design allows for high magnification with remarkably high eye relief — the highest eye relief proportional to focal length of any design before the Nagler, in 1979. The field of view of about 55° makes its performance similar to the Plössl, with the advantage of requiring one less lens.
I bought these Flat Top eyepieces in the early 80's... they are very rare and hard to find. I won't sell these unless I get the right amount of money for them. When I bought these, everyone in the astronomy club wanted them after looking at the views through the 12" reflector we had on site. I have a nice set of 2" Nagler's, and the views you get through these 1.25" eyepieces will rival just about anything. I always wished I could find a set of 2" König eyepieces, but it never happened. They give the best views because of the lens configuration which lets more light through than others with a lot more glass between you and your eye, and the contrast is better than any eyepiece you might try to compare this with.
This König won't disappoint!
NOTE: The graphics are more used than others I have for sale, but the glass is nice with only a few specks of dust. One of my oldest Konig eyepieces.
Filed under: Eyepieces & Accessories