Filters etc...

I was shopping around for some polarizing filters when I realized that there are a lot of different kinds of filters and even many varieties of polarizers. Can anybody tell me the different uses and needs for the various polarizer types? Also, if you use any particular filters regularly, which filters do you use and why?

Its a big topic,

Try this website for general guidance.

http://www.geocities.c​om/cokinfiltersystem/

But since this is a digital forum you will find that most people here prefer to do most of the same things in a computer after the image is taken, rather than with a filter.

I think there is a little confusion here.

The original poster was asking only about polarizers. Mark seemed to be directing the OP to Cokin filters in general. Don't get me wrong. Cokin makes some nice filters, but most are rectangular color and special-purpose filters (which I use), but a polarizing filter is not Cokin's specialty.

Further, it is difficult to simulate a good polarizer simply in Photoshop. If you have a scene that needs to be polarized, then (for any Canon EOS) you must use a circular polarizing filter, and not some rectangular Cokin.

So, the correct answer is that the only polarizer needed is a circular polarizer. Ignore linear polarizers.

Different manufacturers use different types of coatings on their circular polarizers, and those can help, but the basic circular polarizer works fine.

---Bob Gross---

but other than polarizers, is there any inherent advantage in
using actual glass filters as opposed to photoshop's digital
photofilters?

If you have a landscape scene that needs polarization, then you must use a circular polarizing filter on the lens. Photoshop can try a simulation, but there is no good substitute for a proper circular polarizing filter.

Now, within Photoshop, there are all sorts of nifty filter effects, colors, stars, blurs, and all that.

---Bob Gross---

Polarizing Filters

You need to be careful with these for example Hoya produce a number of grades i.e. Green Label, Purple Label plus a few more. The Green label is the cheapest and the poorest quality. I have heard that B+W are a better filter, these are German made, why, because it seems that Hoya multi-coated filters are hard to clean.

Here's a few sites to look at:
http://www.camerafilte​rs.com
http://www.camerahobby​.com/Access-Filters.htm
http://www.schneiderop​tics.com …rs_for_still_ph​otography/
http://www.koodinterna​tional.com/pages/filte​rs.html

I've been buying a few cheap filters on eBay just to check out differences but I've got no answers yet. Theres so many variables with these polarizers, using them is more an art than anything else and this makes it difficult to say any one is better than another.
Good hunting