Amazon.com : 58mm ND Variable Neutral Density Filter for Canon EF 50mm f/1.4 USM Lens : Electronics
Amazon.com : 52mm ND Variable Neutral Density Filter for Nikon 50mm f/1.8D AF Lens : Electronics
New Arrival Fader Variable Nd Filter Adjustable Nd2 To Nd400 Neutral Density For Camera Lens Nd Фильтр Filtro Nd Filtre Nd - Camera Filters - AliExpress