I want to take some night shots of a highway that winds through a canyon near my house. I am not sure how to do it though. I want to do a long exposure. But how long is ling enough to get a really neat effect. Do i need to use my Nuetral Density filter. What aperature should i be using, Stuff like that let me know if you ahve done one. I would love to get any help i can, Thanks
Devin