Which brand would you recommend for the HVX200? Is an "HD" lens necessary (I've seen this advertised). Any brands to stay away from?

James...

See if you can use a linear polarizer before shelling out for a circular. Both work the same. But the circular one usually addresses issues related to light meters or autofocus systems in SLR's, and is more expensive.

If your camera functions properly with a linear polarizer that will save you some cash.

Recommended brands include Schneider, B+W, and Heliopan. Don't go with a cheap filter; you should always use the very best glass you can get.

Is it neccessary to get a circular polariser or will a linear work?

Leonard,

You should always use a Circ-pol rather than linear. The AUTO-FOCUS/EXPOSURE systems in the camera can be fooled by a linear polarizer, which is why ever since Minolta introduced the first mass-produced auto-focus SLR circular polarizers became the de-facto standard.

Linear polarizers are still made (although not in abundance) and within the same filter brand aren't that much less expensive than a circ-pol.

If you shot in MANUAL focus/exp modes 100% of the time then it wouldn't matter which polarizer you used, but since the convenience of AUTO modes brings flexibility to shooting you should just get a Circ-Pol.

Barry's recommended manufacturers are the best way to go. The biggest reason isn't just the quality of glass but the neutrality of the tint in both ND's and Polarizers. Tiffen, Hoya and other "lesser" brands will work but you'll find yourself making color corrections in post that you otherwise wouldn't need to with the best brands.

Case in point: Just yesterday I did a Jib/Crane test at the top of a mountain in the burning-bright Arizona sun (sunburned legs was a bonus). I just couldn't get the exposure/color balance I wanted from either the on-camera LCD or my Marshall monitor regardless what EXP setting I used or even using the built-in ND filters. So, I slapped in a Schneider 1.2 ND and Tru-Pol in my matte box and... voila!... stunning colors, great contrast and the polarizer cut through distant haze allowing the further mountain range to be visible and defined.

No way would I have acheived this color balance with a Tiffen, Hoya or anything else than German-made Schott glass.

I'll see if I can put this test up on my server later this week and you'll see what I mean by great color.