University Optics Abbe Orthos 

Left to right:  25mm, 18mm, 12.5mm, 9mm, 7mm, 6mm, 5mm, and the 4mm

The University Optics Abbe orthoscopic eyepieces are fine examples of simple design and quality construction combining to create a very efficient high-performance ocular at a very (and I do mean very) low cost. These quality eyepieces will provide extremely well defined views with excellent contrast and sharpness. There is however, a price to pay. Due to the design limitation of this type of eyepiece the cost of this performance is offset by some functional limitations. First off eye relief is VERY tight in the shorter focal lengths. If you must wear glasses during your viewing then you would most likely not be able to use any of these above the 12.5mm or perhaps 9mm. The other limitation is the rather narrow field of view. With about a 42 degrees FOV, the use of the higher powers calls for either a motor driven scope to track with or a VERY steady hand and mount.

Considering the price and the performance, the UO othos make a very affordable planetary set. 

If you were sent directly to this page, press Home to enter the site.