The Lucroit holder is specially designed for large-barrel wide- angle lenses such as the Canon TS-E 17mm or the Nikon 14- 24 that otherwise lack a filter solution. Adapters for this holder system fit over the lens to eliminate vignetting with these extreme wide angle lenses. Adapters are available for 19 wide angle lenses with an additional 8 sizes of threaded adaptor rings.
There are a number of wide angle lenses where it is not possible to fit standard filters or holders because the way the barrel of the lens is configured. The holder fits on the lens by a bayonet mount with a retaining rubber ring which holds it in place. It is designed to take 165mm standard filters with grads in 165x200. This means that, unlike other systems, it will not vignette on these wide angle lenses. As it is also available with adapters for standard 72-82mm lenses it now comprises a total high end system for the pro user.