Jump to content


50mm Kellner, rare Royal Optical Brussels, University Optics Sold!

Price - $200.00

Ad Number: 168580

Posted: 17 Apr 2019

Please sign in to message advertiser

This is a rare and odd looking eyepiece. It gets better: you look through the small end. The chrome end fits into a 2" telescope back or diagonal.
Possibly made by Royal Optical, Brussels, and also sold in the US by University Optics.
It was sold by University Optics in the US,
Optics are nice, I cleaned them carefully. Not up to a pro-level, there may be streaks.
Looking through it compared to a Panoptic 35mm both show a similar patch of sky. Tested on a Vixen 102mm ED f/6.4 Orion's belt fits in with enough room to spare on both sides you could almost fit in another star.
The combination of less magnification, less optical elements and older coatings gives you an image than is smaller than the Panoptic, with less contrast and brightness, but also flatter and less edge distortion.
I started a thread on this eyepiece to find out what I had, here on CN. There are more pics in this lin:.

Also see some discussion it this thread, scroll down about 2/3'd of the way:

Price: as a cool collectible $200 obo
Shipping $20 Priority Mail

There is probably not an exact match but a modern but relatively boring 2" 50mm eyepiece that is better for a lower price. If there is, let me know.
Paypal, MO, check.
International shipping I think is around $25-35.


  • Condition Used
  • Location South Pasadena, CA 91030

Advertiser Info

Powered by Classifieds

Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics