Thanks to Sabrina and Chris for the comments re. Fountains Abbey.
Chris. This is a one exposure photo with just normal editing via Lightroom & Photoshop.
Initially I'd set out to go to Aysgarth. In case you don't know of this place it's where the fight scene over the river in Prince of Thieves took place. Quite a lot of fast flowing water and I thought long exposure.
As it happens I spent so much time at Fountains Abbey I didn't get there, which brings me to the reason for this point which ties up with Jediboys post regarding ND filters.
I've never bothered much with NDs as I find them to be to restrictive. If you already possess a Circular polariser then you almost have a variable ND filter, just add a Linear Polariser and you have a variable ND at very little extra cost.
As I had intended visiting Aysgarth I took along my Cir Polariser and Linear one, so I had to use it. The water in the river at Fountains was not very fast flowing, but I took a photo using the polarisers 5 secs @ f/20. This photo below is the result.
Harry