Measurements with the twist-cup extended to the rear glass on my Meopta is roughly 10mm. Without my prescription glasses and using just the twist-cup, its a full frame from 30x to 60x. I don't know the measurement is from the rear glass to my prescription glasses is when the twist-cup is...
I've been using the Meopta Meostar S2 30-60x82 HD for the 2nd year now with my prescribed lenses. I get a really nice full-frame FOV picture from 30 to 60 when wearing my glasses. No vignetting. I suggest on seeing for yourself at the nearest Cabelas if you can.
My setup
I use a Pelican 1450 case with the pluck n' pull foam to carry my spotting scope. I've had this setup for a year now and I'm very happy with it. I wasn't too impressed with the neoprene carrying case at Cabelas so I decided to use a Pelican case.
Pics:
This is what I bring with me when i go out to the West Deserts of Utah for some long range shooting
- IPad with Ballistic's AE
- Kestrel 4500
- Lazer Range Finder
I havent used the Kestrel Atrag, but I do have shooter on both the iPhone and iPad for 9 months now. The interface is user friendly. This is my go to app for ballistic calcs :)