Hoya HMC - ULTRA NDx4 - 67mm

In conditions of extreme light intensity, such as sunshine on snowy mountains or on the beach, or when using a camcorder, ND (Neutral Density) filters are recommended as essential.

Neutral Density filters are often ignored by photographers, but they have several uses and offer the possibility to achieve otherwise unachievable results. ND filters appear grey and reduce the amount of light reaching the film, they have no affect on color balance.

They have four main uses:

1. To enable slow shutter speeds to be used, especially with fast films, to record movement in subjects such as waterfalls, clouds, cars, seas etc.
2. To decrease depth of field by allowing wider apertures to be used, which helps separate subjects from their background.
3. To decrease the effective ISO of high speed film (ie: above ISO400) and allow it to be used outdoors in blight situations.
4. To allow cine and video cameras (which have fixed shutter speeds) to film subjects such as snow, sand or other bright scenes which would normally cause over-exposure.

Filters in this series use our new ULTRA thin rings which, like the Super PL-CIR filter, are designed primarily to avoid vignetting problems which occur with wide angle lenses. The ULTRA series filters use rings just 3mm in thickness, except for the hybrid UV/Polariser which has a 5mm rotating ring. HMC Multicoating is applied to both sides of the filters and they are supplied with our push-on lens caps. The Ultra ND filters use new Multi-Layer Coating technology to produce a neutral transmission curve which gives perfect color balance. We have also introduced hybrid filters in the ULTRA series, these combine the effect of two filters in one (i.e.: PL-CIR and UV together). This means that HOYA ULTRA series filters are the ultimate choice for wide angle lenses - there is no other filter available to exceed the ULTRA specification.