ND filters

[Patriks7]

I have been recently looking into buying some filters, and one that really caught my eye was the ND and grad. ND filter. After searching a bit, I found out that they come in 2, 4 and 8 stop versions. Now, since they aren't cheap, but I feel I need them (especially for landscapes and things like that) I an planning to buy one of each. But I am confused as to which one to go for. Would the 4 stop one be kind of universal and useful for most stuff, or should I get the stronger/weaker one?
BTW, the grad. ND will be a Cokin P filter and the ND filter will most likely be a Hoya filter (haven't decided yet though).
Also, anyone have experience with the Cokin circular polariser? Is it good or should I go with a Hoya?

[Jon]

Well, they aren't 2, 4 and 8 stops - they reduce the light by 2, 4 or 8 times, which works out to 1, 2 or 3 stops respectively. And before I got an ND filter, I'd get a good circular polarizer (Cokin isn't especially). That will double as about a 2 stop ND in operation.

So, get a good CPL (check the Protective Filter FAQ (http://photography-on-the.net/forum/showthread.php?t=368177) for the particulars of good filters), a B+W MRC, a Heliopan SH-PMC or a Hoya S-HMC. If you really need more exposure control than that, your ISO settings and your aperture give you, then get a 3-stop ND.

Grads - the Cokin ones have a reputation for showing a definite colour cast; check out HiTech or Lee instead. Maybe a 2 stop soft grad and a 3-stop hard grad (soft and hard refer to the transition), but wait until you're comfortable working with the CPL first.

[Patriks7]

Oh thanks, I was confused about the stops then. Well guess I will go with the circular polarizer. But which one should I get? When I looked, they don't sell anything like a S HMC circular polarizer here (only UV and some other one) but they do have a Pro1 Digital or something. I was planning on going with Hoya UV filters as well, so I think I'll stick to one company.