Polarizer for Zeiss 15mm f/2.8 ZF.2 lens.

All the shots I posted to this thread (2 posts had photos attached), were taken with just a Marumi polarizer.  The days I took these shots, there was more wind than I like, so I didn't hold the shutter open quite as long as I normally do.  And in some cases it was shady enough were I really didn't need more anyway.

I've also tried the Marumi in combo with a slim B+W ND4 (ND mounted in front....normally I mount ND's before polarizers but this is the slimmest combo in 95mm that I could come up with.)  It vignettes slightly in the deep corners.

I also tried removing the retaining ring from a Hoya ND, mounting the ND glass right in the front of the Marumi and then reversing the retaining ring and basically creating a slim polarizer/ND combo.  This actually vignettes about the same as just using the slim B+W.  I believe I could avoid the vignetting if I could take the same approach with the B+W as I did with the Hoya, but I can't seem to loosen the retaining ring.  Makes me wonder if they used something like Loctite when they assembled it.

In any case, even with UWA lenses, I don't find uneven polarization to be an issue as long as I'm shooting on cloudy days...which are perfect waterfall days.  I don't know if the clouds offer some diffusion that mitigates somewhat the normal single light source (the sun) that usually gives you the hard and fast 90 degree rule.  Just always seems to work for me in the waterfall conditions I shoot.

-Tim