Anyone with GTO zoom experience?

I happened across the GTO zoom EP. Anybody using a pair? Good, bad, indifferent?

7.4mm to 22mm.  Field of view is 63 degrees at the highest power.

Gerald.

I happen to have a pair of these that I use in my binoviewers.

They are exactly what they are, $50 zoom ep's. They have good on axis sharpness, ok contrast and have an issue with stray light inside the ep. I would rate them equal to Sirrius plossls in performance, but with better eye relief and AFOV at higher powers.

Mechanically, they are difficult to use with binoviewers. They are not click stop and the labels are hard to read. I put two zip ties, one on each rotating piece, that gave me a reference for where they were set. The nub of the non-rotating tie is set at 11mm (the middle labeled zoom setting). This allows me to accurately set 3 focal lengths: 7.4mm, 11mm and 22mm.

Bottom line for me, I'm not going to keep them. Average performance coupled with difficult use is not my favorite combination. Also, anyone with diopter adjustments may want to chime in on using rotating zooms with this feature. I know the diopter adjuster rotates the ep, but does rotating the ep effect the diopter adjustment. If so, these would be an even more difficult solution.

Clear skies,

Tom