I bought a 10-stop ND filter a couple of days ago. Didn't do my research properly, and bought about the cheapest, which I now find is not recommended as it gives a strong colour cast. Oh well, back to Photoshop, then... Also I didn't realise until I was out in the field that to multiply the shutter speed by X 1000 wasn't as easy in my maths-challenged head as I had assumed. I wasn't even prepared for the obvious fact that the camera can't register focus or exposure through the filter: it's pretty much like putting a lens cap on. Better try again soon, with proper prep.