Hi, I'm the author of the post. We use this hack on the bridge of Navy ships. The red density required is pretty significant (the plastic we used was a little thinner than a #2 pencil). We would velcro it over the screen. The velcro leaves a gap which creates a fairly significant light leak around the edges. First iteration, so better, but a long ways to go. Comparing that to Blacktree's nocturne, software is at least a significant part of the solution.