It's a bit absurd to have an article about this and not include any screenshots of the actual white blocks used by the lightgun to detect targets. This is a better explanation with visuals; it actually used two screens to do the detection:<p><a href="https://www.scienceabc.com/innovation/how-did-the-nintendo-game-duck-hunt-work.html" rel="nofollow">https://www.scienceabc.com/innovation/how-did-the-nintendo-g...</a>
It's also well explained (waaay more technical and in depth) by the "Retro Game Mechanics Explained" channel on YouTube: <a href="https://youtu.be/2Dw7NFm1ZfY?t=975" rel="nofollow">https://youtu.be/2Dw7NFm1ZfY?t=975</a>
Simply a great example of using engineering and inventiveness to solve the problem they had. I remember noticing the screen having a flash, but because it coincided with the 'bang!' noise it felt natural.
so could it easily be tricked by putting a finger over it and quickly removing it in front of a light? or it's too small of a window to trick? a strobe light could fool it?