About Filters

On my on-going quest to learn everything I can about using my 20D, I've finally come to filters. I did a quick search on the this board for threads about filters and didn't find much. Anyone care to send me in the right direction on learning more about all the kinds of filters and what you would use for what situations? Thank you guys.

Oh and just a quick question since I think I'm about to purchase a 70-200mm F/4L, What's a good filter I should buy along with it. I see all this UV, Haze, coatings and things, etc. I just need a quick suggestion on what to get for starters to have it with the lens when it arrives. My first use for the lens would be a trip to my local Zoo and maybe take it to an Orioles' game if they allow that lens in the park.

The main filters you should concern yourself about are UV and polarizing. UV filters are for protection, if you get one get a high quality one - no point buying good glass and putting crap in front of them. If you get one, get a multicoated one, Hoya and B+W are the most widely recommend. I got a good B+W filter for my 70-200 IS that's on the way, I have a hoya pro-1 and I find it hard to clean. B+W cost more, but I thought i'd give it a go - why buy an expensive lens and cripple it? You don't need the ultra-thin ones or stackable ones, buy get a good multicoated one.

Polarizing filters are the other ones you should really worry about. What they do can't be done in photoshop - there are plenty of descriptions around about what they do. They're great for sunny days or for cutting down reflections on glass, but you lose maybe one stop of light, give or take.

HTH.

Ok, I'll order a B+W 67mm UV Haze 010 (MRC) Multi-Resistant Coating Glass Filter. The stackable and the slim version are more than twice the price of this one :O