APM UW 30 mm 80° - any tests?

[planetman83]

Has anyone tried this eyepiece? I am not talking about the UFF. This is too cheap, it costs about 100€. 

[Louis D]

It's the same as all the other 30mm KK Widefield III clones.  I have one and it works great in the center 40 degrees and gets progressively worse due to field curvature and astigmatism toward the edge.  It does not suffer from chromatic aberration of the exit pupil like the 30mm ES-82, though, so there is no ring of fire or odd fringe colors on objects at the edge.  They're just highly astigmatic even when refocused.  In the center, I'd say it is sharper and contrastier than the 30mm ES-82.  It's great for eyeglass wearers with a huge eye lens and an easy to hold view.  The field stop is soft because it uses the barrel for one.  If you can buy one (or a similar clone) for $50 to $60 used, they're a great deal.