This S6 PRO Circular IR NDfor S6 150mm Holder from NiSi provides a 3-stop exposure reduction. Its 0.9 optical density creates a darkening of the entire image, allowing you to photograph with a wider aperture or slower shutter speed without overexposing your image. By slowing your exposure time or increasing your aperture, you can control depth of field and convey movement more easily. The NiSi Pro Nano Coating helps to reduce unwanted reflections and provides a waterproof and scratch-resistant layer to assist in the cleaning of unwanted fingerprints, dust, and water stains.