I just purchased Nikon 17-55 lens.
1. How do I get the benefit of the polarizer(slim) for glare/reflections in damp waterfall scenes and the ND to slow down exposure? There are no threads on front of polarizer
2. Similar situation on coastal sunset/sunrise scenes with grad nd
1. Set your camera to manual exposure. The ND means you can use a slower shutter speed (1/8th., 1/30th?) so there is a nice water blur. The Pola will help with even longer exposures (1 sec, 1/2 sec) AND rotate it to reduce reflections in the water.
2. Actually, a very different situation. At sunset the sky is very bright (but pretty), the ground is very dark. A graduated ND helps balance the exposure. Put the ND on the lens so that the dark part is at the top. Try exposures– darker , lighter– to find what looks good.