All of the 150 x 150 Lee Filters will have the issue of the catching a reflection from the back. In the field I always carried a black lens soft cloth, the ones with the velcro tabs, and wrapped it over the top to block out light. The Black foil would work also
and I like it's design as it will more than likely stay in place better.
Cokin Pro, Lee, for sure have the problem on the larger filters, not sure about the Fotodiox solution.
As this rig seems just like the Lee setup for the Nikon 14-24, currently there is no CL-PL round filter that you can rotate for the 150 x 150 size filters. When I used my Cokin Pro on the older Mamiya 28, (I made a special mount adapter
for the Cokin pro which allowed it to slide up on the hood of the 28mm) I never used a grad since I tended to need a CL-PL also. I used a 5.65 x 5.65 Schneider glass CL-PL sheet filter mounted to the very front of the Cokin pro. This
allowed me 1 internal filter which tended to me a 0.9 or 0.6 ND. By it's design the Cokin allowed rotation around it's axis, so you could still rotate the sheet filter. This excluded the use of a grad. ND or color filter.
Maybe Lee has a CL-PL in the works for this rig as I am pretty sure this setup is 150 x 150 so anything they make could also be used by Nikon 14-24 users.
Back to Fred's point, if the CL-PL fits inside and was round like the smaller CL-PL's from Lee, then yes each time you rotated it you would more than likely have to pull the sheet filter on the outside to get at the CL-PL
Still better than nothing, which was what the users of the old 28mm Mamiya had for years.
Paul
