There are some tutorials on youtube.
One I have watched is
View: https://www.youtube.com/watch?v=_u3_-7nSwwM
. A very in depth chat about it but one tip I did pick up is that lightroom or Abobe raw converter will not go far enough to restore the white balance and therefore get rid of the red hue. To do that I had to use Canon's own software (I used a Canon 650D to take the picture).
Until I found that out I was rather disappointed with the filter but with this information I did go back and get the 1st trial images I had taken and got the hue looking better. I must get out and have another go with the filter and see what I can come up with.