The Tiffen 4.5" Round Neutral Density (ND) 0.9 filter has several uses and offers the ability to achieve results that would otherwise be impossible.

It allows the photographer to adjust exposure without affecting colour balance. ND filters appear grey and reduce the amount of light reaching either a digital camera's sensor or the film plane of a traditional camera.

Neutral density filters are used to create unusual special effects such as capturing the "blur" of cascading water in a waterfall or the swirling effect of urban traffic.

Tiffen's ColorCore glass is produced by a process that permanently laminates the filter material between two pieces of optical glass polished to tolerances of one ten-thousandth of an inch, then mounted in precision aluminium rings. Determining which neutral density filter gives ideal results for a given lighting situation requires knowledge, experience and a collection of such filters.

Neutral density filters have four main uses
-To enable the use of slow shutter speeds, particularly with fast films, to record movement of subjects such as waterfalls, clouds or cars
-To decrease depth of field by allowing the use of wider apertures, which helps to separate subjects from their background
-To decrease the effective ISO of fast films (above ISO 400) and allow their use outdoors in bright situations
-To allow film and video cameras (which have fixed shutter speeds) to film subjects such as snow, sand or other bright scenes which could cause overexposure

ColorCore Technology
-Tiffen filters are manufactured using ColorCore technology, an exclusive closely guarded process that permanently laminates the filter material between two pieces of optical glass polished to tolerances of one ten-thousandth of an inch, then mounted in precision metal rings
-The ColorCore process allows Tiffen to control the colour and density of their filters, and the characteristics of special effects filters with far greater precision than typical dyed-in-the-mass filters, which generally show colour and density variations

Superior Quality
-Hollywood's major film studios trust Tiffen filters for their multi-million pound productions. Superior quality and design make Tiffen the preferred choice of filmmakers, professional photographers and even NASA
-Tiffen has also received an Emmy from the Academy of Television Arts and Sciences for engineering excellence