I use V series 20 years
I use PME45
PME 90 is not usefull
coverage is 100%
even easier to focus and diopter correction
and sight corrected image (as an SLR prism)
Mine does not get unmount from 503CW
I always used the 45 degree thing, and years after selling the outfit I had another look at a 500 Series with my old prism (45 degree)-type and it felt really strange, as if looking uphill. Yet, when I had it, I never felt the oddness at all; don't let initial strangeness put you off: it's a great way of viewing. I hated the standard WLF. What's the point of using it without the right-way-round advantage available with a prism? Apart from anything else, keeping your eyes and side of the nose hard against these metal edges gets very uncomfortable in a studio shoot situation if you shoot people, which means your eyes seldom stray from the screen... comfort is good.