Tiffen 4X5.650 Full Spectrum IRND 1.8

Features

Full Spectrum IR Neutral Density eliminates far red starting at 680nm which increases with the use of standard neutral density filters.

The Neutral Density filter is used to control light as well as to gain more control over depth of field. Up to now ND filters made with dyes did this job, but passed small amounts of far red to near infra-red light to create their transitional slope between attenuating visual and passing infra-red. In addition to the visual spectrum, digital imaging devices are sensitive to infra-red. This infra-red can have an effect on the quality and the color of the image. Digital imaging devices require higher grade neutral density filters but are sensitive to infra-red (IR). This IR pollution has an adverse effect on the quality and the color rendition of the images - stealing contrast and color, resulting in unwanted color shifts. Greens become a reddish muddy brown and blacks have a magenta hue.

In addition, infrared has a different focal length than visible light: therefore, your images may also appear out of focus. To combat this problem, some camera manufacturers use an IR blocking filter in front of the device - most notably, the Sony F and EX Series, ARRI Alexa and the Panavision Genesis. However, when you combine a neutral density filter with cameras containing a built in IR blocking filter, the result is a spike in the far red and near infra-red.

For this purpose, Tiffen pioneered the Full Spectrum IR ND Filters designed to provide a true neutral density into the IR spectrum to correct this issue. Tiffen´s Full Spectrum IR ND Filters now allow for the use of heavier grades of Neutral Density filters needed for these hi-definition cameras while, at the same time, maintaining color balance.