This filter is for photography purposes only. It cannot be used for observing solar eclipses. When photographing solar eclipses, use it in combination with (ND8) or (ND400) as needed. High-density ND filter using ND glass [8 2/3-stop light reduction] Recommended for long exposures and solar photography during the day Filter diameter: 77mm / [MCND400 Pro 77S] MCND400 Pro 77S High-density ND filter using ND glass Reduces light output to 1/400, or the equivalent of an 8 2/3-stop shutter speed Allows for ultra-slow shutter speeds of tens of seconds to several minutes during the daytime outdoors ■ Specifications ■ Filter diameter: 77mm *This filter is for photography purposes only. It cannot be used for observing solar eclipses. When photographing solar eclipses, use it in combination with ND8 or ND400 as needed.