Again, Murray-thank you. I did some more tests today: Pentax 645D, 35mm MF lens. I focused the camera with a Circular Polarizer in place. I then held the Polarizer so it would not turn, and stacked the 10 stop ND. I used f16 and Aperature Priority, and dialed in +.3, 1 stop and 2 stops. I got rather consistent exposure with and without the polarizer at +2 stops. I zeroed in by checking the histogram after every shot. It seems in the field I can start at f16, + 2 stops dialed in, then fine tune from there. The polarizer does work with the ND. I have a "Whibal" card which I have to re-learn how to use it, to help with the white balance
Appreciate your help....if I get a keeper, I will post.
Dave