High Definition Lens Filters

[videobread]

Are "High Definition" Lens Filters required? I know HD lens are required but, how about a simple, say, UV or polarizing filter? It's flat glass. I see some sold as HD and some not. Is it just marketing. I have UV filters to protect the lens'. Made in Japan, etc, looks good but, not HD. I've seen write-ups on Hoya polarizing filters claiming to be "4 times harder, 25% higher light transmission with water repellent, scratch and stain resistant multi coating." All that quality product info is not about HD vs standard though. My main concern is focus. Any comment?

[nic2k4]

You're right to question the need for special HD lens filters. HD lens are required to allow capturing the full field of view of the HD sensor; basically it comes down to the size and shape of the rectangular mask at the rear of the lens, just in front of the sensor. A filter sits in front of the lens, the only limitations on it are for it to let the maximum amount of light through without changing the color, creating distortion and causing vignetting.

[Cornucopia]

Unlike lenses, which have intricate and complex optical properties that require some serious technological precision (and $$$) to make them capable of resolving a good HD image, filters are generally simple PLANES in the optical path. They rarely affect the optics to a point where they would lower the resolving power under HD quality - they'd have to be pretty SHITTY if they did!

There could be a few exceptions to this: Polarizers, Diffusion, and the various special effects filters: Refraction/Star/MultiImage, Mist/Glow/Halo, etc.
That's because they can modify the path the image takes or utilize physical "barrier" methods to induce the effect.

But all the usual ones: ND, Cool/Warm/Color/Correcting, UV - as long as their optics are CLEAR/CLEAN to begin with, it shouldn't make a difference...

Scott

[aedipuss]

i would spend a couple dollars more and at least get a name brand to get good glass, and decent metal ring. i've used tiffen ultra clear with good success with dslr camera lenses.

[greymalkin]

thanks for the info cornucopia..I really couldn't see how a film or peice of glass had ANYTHING to do with the resolution of the recording device .