I don't think that's the problem. Without any fanfare Leica has been using Uppendahl prisms in some of their Geovid models.
Henry:
Thanks for that cut away of the Leica's. It would be nice to also show
a typical Abbe Koenig and Schmidt Pechan prism type to add to the
current rangefinder models available.
Zeiss has now introduced a new rangefinder binocular based on the HT
that has the most advance electronics to communicate by bluetooth to a riflescope for data needed on the range.
This could be another whole topic, but in my short search, I did find that
Leica has described that the previous Geovid model shown has a "compact roof
prism" design. I suppose that means Uppendahl.
Leica is all about function and style, and I am wondering if the perger porro
has advantages over the Uppendahl.
Engineering the electronic components needed for the rangefinder requires
space and room for batteries.
Swarovski has the Schmidt Pechan prisms, and they use a lump for the
electronics on the back side. The others do not.
Jerry