This polarizer topic is interesting. I remember those from Physics class in college. My professor told me that polarizers mearly pass natural light into one plane.

Also, concerning getting a light polarizer. According to the equation for a linear polarizer, the iradiance of light passing through it is always halfed. So this could only be useful in very bright scenes?

In practical usage, does a neutral density filter perform a similar function? Can/should they be used together? If no to both questions, then why don't the prosumer cameras include them?

Very interesting,

Polarizers typically reduce the light by 1.5 stops to 2 stops of light. The saturation of colors is a result of reducing reflections from reflective surfaces. The shinny surfaces create polarized light and degrades the image. The polarizing filter prevents the polarized light from entering the lens, thus giving the effect of saturating colors. Use of polarizing filters indoors is usually not recommended due to the light loss.

Additionally, no, neutral density (ND) filters do not serve the same purpose. ND filters simply reduce all light through the lens. They do not polarize the light.

I haven't seen the B+W polarizers. Are they actually lighter? The filter factor is the same as for a Tiffen. Grant

I have two. Honestly, I can't technically confirm that but they do appear a bit lighter than my Tiffen. However, it's largely a moot point, as you would be using it in bright sunlit settings anyway.

Are we talking lighter as in weight (B+W is probably heavier they're made with brass mounts) or optical density? The optical density is not an accurate gauge of their effectiveness.

I guess I wouldn't be totally concerned about it, but when I said the B+W polarizers are lighter... I meant less dark. The construction is super solid.

With such a BIG lens 72mm it's a bit of a job to clean a MC filter properly. I use some stuff called Formula MC that I got from www.2filter.com and it works pretty good.

B&H has the best price on polarizers... I coulda' saved close to $20 if I'd have bought mine from them.

The one I'm using now is called an FPRO. It's a B+W multi-coated job and it's significantly less dark then the Tiffen's I've used in the past.

The reason I care about having a lighter polarizer is 'cause I use mine indoors to eliminate glass also. I should post some frame grabs from Shed Aquarium in Chicago. There's a few shots where I had to turn the polarizer while shooting and it goes from a window reflecting some young ladies... to what looks like a huge fish floating in mid-air.

Of course I wouldn't get bent on paying the highest possible price for a polarizer either... they all work and I don't know if I could justify exactly why I like B+W so much... but I do.