Marumi ND 8X 52mm
Marumi makes 2x ND center filters in 62, 67, 72, and 77mm. They are neutral gray in the center, graduating to transparent at the edges. They are used primarily to reduce vignetting which occurs with large format cameras when using wide angle lenses. Center filters help give an evenly illuminated shot. This center filter requires an exposure correction of 1 f-stop.
Multicoated to minimize reflection at the filter surfaces which reduces flare and ghosting.