Hi Dave.
I do have the Nikon 105 (tried to list my gear in the 'signature' panel, but was unsuccessful in getting it to show). As I don't foresee a step-down ring hitting the pockets hard, I may just get one to try a couple of the filters out. You may laugh at my naivety, but I had thought/hoped that the left-most colored filter (in my first photo) was a ND filter
. I had been hearing a lot about the advantage of using them, but have since gained information that such filters do not attach to the lens. Supposedly, there is a squared type of housing which attaches directly to the lens, and the ND filters just slide into a recessed area of said housing.
Oh well, I guess we learn something every day
.