 The Hexfield Viewscreens iris mechanism was originally thought of  by Best Brains, but they were unable to built it. As such the first  few incarnations of the Hexfield ranged from nothing at all to a  window shade to a slightly more advanced window shade. However,  shortly into season 2s production Jim Mallon found an add in a  magazine for a person who manufactures large iris. The builder was  located not too far from BBIs office and being a fan of the show he  agreed to build the Hexfield for cost of materials.