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Keep watching the video - he builds Fresnel lens versions at the end of the video. The satellite dish is more dramatic so I don't blame him for leading with it

• Animats 6y ago
  The idea is to build this as a light box behind a standard windowpane frame. Like this one.[1] With a 120mm short focal length, the unit only needs to be about 150 - 200mm deep, if you angled the optics so you get light at a 30 degree angle or so. (Horizontal sun rays would look wrong.) That's a convenient size; you could hang it on a wall, like a rather bulky picture. [1] https://www.walmart.com/ip/Darice-Wooden-Window-Pane-w-6-Panes-17-x-17-inches/107629033 https://www.walmart.com/ip/Darice-Wooden-Window-Pane-w-6-Pan...