HOYA, the world renowned optical glass manufacturer, presents an innovative high definition line of filters..

HARDENED GLASS Hardened optical glass that has 4 times the breaking strength in ANSI standardized testing (ANSI Z80.3 : 2001) where a steel balls of varying size and weight were dropped from a height of 50 inches onto the glass. TEST MOVIE ( QuickTime Movie File ) TEST 1 NON HD GLASS (2.5MB) HOYA HD GLASS (2.9MB)       TEST 2 NON HD GLASS (8.2MB) HOYA HD GLASS (3.5MB)       WATERPROOF / SCRATCH & STAIN RESISTANT MULTI-COATING Specialized coatings that are not just water-proof to repel water spots but also hardened to be scratch and stain resistant. Of course these coatings are from HOYA so they are greatly reduce reflections off the surface of the glass allowing you to capture more light in your photos.

I found this review of the Hoya Filters on  http://www.kenrockwell.com/hoya/hd-filters.htm#intro It is a very good and honest review

Well worth a read

These new Hoya HD filters really are something special. "HD" is a marketing name, not a technical designation. Hoya's HD filters come in circular polarizers (C-PL) and UV (protection) types.

I'm always skeptical, but these new Hoyas really do what they claim.

Not only do they have magic coatings which really do repel dirt and fingerprints, the polarizing filters allow about one full stop more light to come through, effectively giving you an extra stop of either ISO, lens speed or shutter speed, for free!

Just like the magic coating on the back of the Canon SD880, these multicoated filters don't pick up fingerprints.

Put your thumb on one, and the fingerprint just doesn't stick. If you go out of your way to get fingerprints on it, they clean right off, too.

This has been the biggest problem with multicoated filters: they are easy to get smudged, and tough to clean. These new HD filters really are very different.

I didn't try, but Glenn Nash of THK cheerfully kept whacking one of these on the rounded edge the display table at PMA 2009, and it wouldn't break. (Glenn cautions that if you hit it too hard or on a pointed object, you can get it to break, so don't push your luck.)

These HD (heavy-duty) filters use specially hardened glass that is far more resistant to breakage than other optical glass.

Hoya isn't kidding. Hoya is the world's largest maker of optical glass. They know what they're doing.

More importantly, the new HD polarizing filters use magic polarizing material that loses less light. Most polarizers lose two stops of light. I measured this one, and it loses only 1 and 1/6 stop (one and one-sixth of a stop) of light. This means sharper photos at lower ISOs than using regular polarizers, about one full stop better.

How does Hoya do this? Easy: they use the same extra-expensive, extra efficient polarizing material as is used in LCD panels, where brightness and efficiency are everything.

The new HD Hoya polarizers let in more light, but don't lose any polarizing ability. If you want to see how well they work, look at your LCD TV through one. Rotate it, and the LCD screen will go completely BLACK!

By comparison, the superb Nikon circular polarizer loses 1-1/2 stops, while common polarizers lose about 2 stops of light.

Hoya HD polarizers have a thin mount only 5mm thick.

Since the HD glass is so tough, it can be made thinner and therefore weigh less. The 77mm Hoya HD polarizer weighs 32.7g, while the superb Nikon 77mm Polarizer weighs 35.4g. The Nikon does have a slightly thinner 4.88mm mount, but hey, this lighter filter is what Glenn was banging on the counter. Try that with a Nikon.

The Hoya HD polarizers come in 52mm, 55mm, 58mm, 62mm, 67mm, 72mm, 77mm and 82mm.

Hoya HD UV filters come in the same sizes. They don't get you more light as do the polarizers, but they do have the same super-tough glass and coatings which repel fingerprints.

These aren't cheap, but they are the best I've ever seen, and they don't wear out. You'll use this filter on your next lens, and certainly several new cameras. Good filters are an even better long-term-investment than lenses. I'm still using the Hoya 77mm polarizer I got back in 1999, and the 52mm Nikon polarizer I got back in 1992. I got this new 82mm Hoya HD polarizer for my Canon 16-35mm L lens; and I'm sure it will last longer than I will. (Caution: don't use polarizers at the 16mm end of any lens, the sky will look weird.)

Hoya's Pro 1 Digital filters are less expensive, and still excellent. They use regular optical glass and weigh 34.4g in 77mm size, with a 5.4mm thick mounting ring. The Pro-1 polarizers lose 1 2/3 stops of light and come in 52mm, 55mm, 58mm, 62mm, 67mm, 72mm, 77mm and 82mm. The Nikon is a better filter at about the same price, but doesn't come in all the sizes that the Hoya Pro 1s do.

The Hoya HD filters are significantly better than anything I've ever used due to their high durability and superior light transmission.