I bought some cheap second hand carded filters and holder to play with.
Not very well composed, the tide was beating me, was lapping the tri pod by the time I fired the Mamiya medium format. Still nice effect using a 4 stop ND.
Using 2 filters a half red for the sky and a half blue for the water. Again should of composed it better, but did a 50/50 shot to see what the filters would do. Most shots on the roll were badly exposed, because I didnt know how much compensation to give, know now.
This is a 8 x 10print scan, 2 x stop graded burn of sky and 1 stop graded doge of the post and potassium ferricyanide on the white wash.