Produce Motion Blur This filter allows to 8-times longer shutter speed instead of reducing the aperture to limit light instantly. Widely used for photographs of waterfalls and other nature scenes to emphasize movement. Reduce the amount of light This filter reduce the amount of light entering the lens so wider apertures can be selected. General care and handling of the photographic filter 1. Use filter carefully and always keep it clean. When cleaning use cleaning tissue or cleaning cloth. But before that remove as much dust and dirt as possible from the lens with a blower or brush. 2. Avoid unnecessary cleaning of your filter. 3. Filter is made of glass. When it is broken glass fragments may injure. 4. Do not disassemble filter by yourself. 5. When the filter is not attached to the lens, store it away from sharp objects. They may damage the filter glass. 6. Keep filter away from children. 7. Keep filters in plastic hard-sided case or filter pouch. 8. Keep filters dry and away from direct sun light. 9. Avoid storage in high humidity environment. Moisture drops due to the high humidity or dew on the filter can burn the coating and create traces on the glass surface that can be hardly wiped off.