I just mark the polarizer exterior where maximum strength is.
If the exact amount or effect of the polarizer is critical, that’d be a specific use case and maybe the SLR is needed. Of course then we can see exactly what the effect will be, or maybe it will be too dark to focus with confidence..
For my needs, I have a pretty good idea what is going to happen. In fact I’m sitting here right now at the beach (30C
), #32 on the roll, all with cpl and a rangefinder.
Whatever camera I’m using i feel it’s better to have some idea what you’ll end up with before you put it to your eye.
But yes absolutely, cpl, flare, the lens cap, my thumb, these are amongst the things i never see through a camera viewfinder.