Neutral density filter ND 1.8. Gray filter with a diameter of 67 mm. This neutral density filter reduces exposure by 6 stops, allowing for better control over exposure settings. By uniformly increasing the density across the entire image area, it can decrease depth of field to isolate the subject. The shutter speed can be shortened to enhance image blur and amplify the impression of movement or to smooth the appearance of flowing water. Equipped with exclusive Multi-Resistant Coating (MRC) Nano-Premium coating technology. Material: brass. This BW gray filter, which reduces the aperture by six stops, is considered an extreme filter in image photography. It transforms 1/60 s into a full second of exposure time without changing the aperture (and depth of field). Flowing water is rendered delicately. A tripod is required in any case. ND filters extend exposure time. A neutral density filter (ND filter) or gray filter blocks a portion of incoming light. With a gray filter, you significantly extend the exposure time, achieving effects such as blurred water or preventing overexposure in bright sunlight with an open aperture.