My 12mm bullet arrived. Hooked up temporarily, compared handheld side by side to a 4mm. Amazing difference in a way, after trialing a 2.8 and 4mm.
In the living room, pointing around, it only gives you a sliver and basically just shows the flat screen TV, instead of the whole wall ... haha.
I think this will work well for a driveway closeup and maybe a wildlife cam shooting over a bit of a distance into an open space in the back yard.
Ballpark guide, from the looks of it, if you have a 4mm and are curious what a 12 mm would show, divide the 4mm on screen image in 3 equally spaced columns and 3 rows (grid of 9); then the center rectangle is what the 12 mm shows.
I'll probably order a 2-12 dome next. More money, but enclosed protection and convenience of dialing in the FOV and focus.