Brilliant add on

I am using a set of amazing set of combined ND and Circular polarising filters from SRP ND 8 & 16, had to get mine shipped from the states, but well worth the money.

  They seem to keep the ISO at the desired level.

Review here

  

https://www.youtube.com/watch?v=zOetyiSC7kU

They should keep the shutter speed to the desired level to create motion blur