The NiSi 4 x 5.65″ IRND Filter is a set of IRND filters that provides 1-4 stops of exposure reduction. Its density creates a darkening of the entire image, allowing you to photograph with a wider aperture or slower shutter speed than normally required. By slowing your exposure time or increasing your aperture, you are able to control depth of field and convey movement more easily. Neutral density filters are intended to not affect the coloration of the image and are ideal for pairing with other filters.
Why do you need IRND as opposed to regular ND?
Traditional NDs block visible spectrum light only. However, unlike photographic film stocks, the imaging devices in high-definition cameras are inherently sensitive to infrared light. A 10 stop “ND” filter would overwhelm your sensor with 1028x more infrared than visible light, causing nasty color shifts and artifacts.
