There's only so much a barndoor can do. Fin-S makes up for those limitations. It clamps on an Omni or DP Barndoor leaf; reaches out and pivots in precisely to shape the beam and shade or shadow part of the scene. It provides a sharper, more precise cut than barndoors alone and simplifies the job of cutting lens flare. Two panels can hold a gel. Comes with clamping Piv-it.