I called Glolab to see about getting a bulk shipment of fresnel lenses. The saleman asked what application I was going to use them in and I told him game cams. Well, he let me in on a little secret. Glolab is developing a motion sensor board aimed at the game cam market for do it yourselfers like us. The board will have the PIR sensor, amplifier, a temperature compensated sensitivity adjustment, setable delay between triggers, test led output, and an event counter (I think he said a day and night sensor too). He said they expect to have it out around summer and are testing it right now. It will be interesting to see the cost of the board. My guess will be between 50 and 70 bucks. They must be reading this message board!