SJ52 GND8 100mm x 150mm GND MC Filter Multi-Coated Optical Glass,Nano Coating Technology

SKU: KF01.1168

A
There does'nt appear to be a facility for holding a circular polariser on this system (i.e. the type you can rotate in the mount) 
A
You need a 100mm square filter holder and 77mm adaptor ring. Format hitech is probably the more affordable. Personally I use Lee filter system. 
A
I personally haven’t noticed this.. using the 1.8 … there is a tiny bit of discolouration using the 10 stop..This is so easily corrected using something like light room Correcting the colour temperature.