HJL,
I enjoyed reading this article about inexpensive thermal/IR force multipliers, but there are a few things I’d like to mention about these. Turning on any smart phone in a combat situation would look like someone holding up a 60” flat screen to anyone with real night vision and would probably draw the attention of the naked eye too. PVS 4s can spot a man puffing on a cigarette from over a mile away, so imagine what the light emitted from a smart phone looks like whether it’s facing you or not. To use a thermal smart phone effectively, you’d need a shroud around it to prevent all the light from escaping and being picked up by other night vision devices. I suppose a baseball cap, some bailing wire, and some duct tape strategerie might make a decent smartphone/thermal/harness/shroud for hands-free and inconspicuous use. Smart phones also get hot while in use, so they’d be visible on thermal too. Also, another cheap but extremely effective night vision device is the one that came with the Call of Duty 2 video game. They are cheap, made in China, available on eBay, but are very effective in the dark. They’re fully shrouded too. – G.G.