Lee100 Filter Holder – What is it? The Lee100 Filter Holder is a completely redesigned version of the popular and versatile 100mm filter holder for square (and rectangular filters). Like its predecessor, the Foundation holder which I have, the Lee100 Filter Holder also stands out for being one of the few that accepts a polariser – it fits to the front of the holder to allow the use of older, more affordable polyester filters, or ‘gels’ which would otherwise interfere optically. The holder attaches to the lens using a specific adapter ring, so you need only buy a ring for each different size diameter thread, instead of multiple filters of…