Sony HZC-VND55F Variable ND Software License

HZC-VND55F is a permanent software option that unlocks variable neutral density (ND) control on a compatible Sony system camera, letting an operator dial exposure down electronically instead of swapping physical ND filters mid-shoot. That kind of on-the-fly exposure control matters most for productions shooting in changing light, where stopping to change a filter costs time the shot doesn't have.

It's a one-time purchase applied to the specific camera it licenses, part of the same HZC family of format and feature options Sony sells for its system camera line.