An example of Ian's great work is below:
Upon reading the description I rushed down to my local camera shop to purchase the darkest Cokin P Series ND filter I could.I was informed to stack an ND8 along with my current ND4 to produce a similar effect. This by no means produced the same results and gave a horrible artificial red tinge (OK I know the picture above is black and white but I am sure that it was correctly coloured from the offset). I scratched my head for ages and thought that it must be something that I was doing wrong.
It turns out that this is a common complaint and is summed up perfectly within the following thread/entry:
Cokins not so neutral density filter
I am therefore going to switch to either the B&W filters (as used by Ian, thanks for the info) or the Lee Filters, yet more cost!! Hopefully I will have some results to post soon and will be happy with the output from these.
A useful article that I found for determining the rating of these filters is:
Single Serving Photo - Neutral Density Filters
