So you know how much I love my ND10 filter. Well I've discovered another thing it does brilliantly - it makes things disappear!
Confused? I'll explain. The next shot shows a shot of the Bass Rock off the Coast of Scotland (click on the images for a larger version).
Nice enough eh? I mean, I guess some of the charm of the Bass Rock is all those seagulls and gannets swirling around it and it's lovely white colour from all the guano! Well what would it look like without the birds? Have a look...
Voila! They've all gone. The second shot is a 30 second exposure with the ND10 filter. Everything that's moving doesn't stay in one place long enough to create an image on the sensor. "Ghosts" can be created by slow moving things or things that stop for a bit before moving on but these are easily removed by the clone or heal tool in any processing software.
Neat trick though!