I went for a nice trip to the beach yesterday and used my Cokin ND filters and the end result was absolute trash. Obviously I am doing something drastically wrong and I'm annoyed that it was the perfect chance to have a play with the filters but couldn't figure out what I was doing wrong, and yet I won't have the opportunity to go the beach again for a while.

Anyhow, what I did was to meter with the filter(s) in place and take the shots (alternating between ND8 and ND8+ND4 together) - the end results was every shot was highly over exposed.

I googled the process, and became even more confused. A lot of sites state to meter before you put the filter on and then put it on, keeping the metered settings and just shoot. Another site said you need to meter first, put the filter on and then adjust the speed to compensate for the size of the ND filter (totally lost me).

Can someone please explain the correct process to follow when using an ND filter so my next trip to the beach won't be such a catastrophe. My graduated ND filters are 2, 4, 8 and I am waiting for my Hoya ND400 to arrive.

Many thanks,
Liz