In my most recent side-by-side, low light comparison of 7 different scopes (2 weeks ago and all set at 6X power), the 3.5X-10X-50 Z-con plex outperformed by several minutes the 3X-9X-40 Z-con plex, in terms of placing the crosshair on a target and seeing it well enough to make a good shot at some 75 yards. That said though, the 3.5X-10X-44 Z-con with #4 reticle moved ahead of the 50 plex by several minutes. While I could still see the target itself a little clearer with the 50 than the 44, the thin sections of the 50's crosshair had faded several minutes before. Also tested were a 36MM VX-III, which faded first followed by a 42MM Nikon Monarch, which lagged several minutes behind the 40 Z-con. The top of the heap by far was a 3X-12X-56 Meostar with illuminated #4 reticle. Of course this is how it all played out to my eyes. Others might see things differently. The results of the latest test mirrored, for the most part, other low light tests I have run during the last several years. It finally convinced me to have two of my 50 Z-con plexes converted to #4 reticles. Too late however. A call to Zeiss 5 days ago revealed that Zeiss stopped all conversion of Z-con reticles two weeks ago.