I bought a plastic fresnel lens from a dollar store, playing with it I imagined that if mounted in a helmet it could be used for an interesting costume. The idea was to position the lens about 20 to 30 cm in front of the user face so the magnifying effect will really show and to place some lights (LEDs) inside the helmet illuminating the user face to provide a TV like effect. During the weekend of Halloween 2010 I built this prototype using plastic fresnel lens, scratch wood materials, a skiing helmet, a PICAXE micro-controller with 8 LEDs, a rechargeable battery and a voltage regulator. A simple program to cycle through various light patterns was written.
It took me about 10 hours to do the prototype and it performed very well. It is a helmet that creates a really cool effect, specially at dark places or at night. The only real issue I found is that for the person wearing it looking through the fresnel lens is very difficult, specially with the lights flashing directly in front. If I ever do a second generation prototype I will use a couple of mirrors to provide a periscope type sight for the user and although the helmet is lighter that it looks and feels very comfortable as it is well balanced I would build a future version with lighter materials.
WARNING: Always use the helmet during night or indoors, never during day time and outdoors and never look at the sun with the helmet on. The lens will magnify the suns rays and could cause severe burns or eye damage to the user.
WARNING: Always use the helmet during night or indoors, never during day time and outdoors and never look at the sun with the helmet on. The lens will magnify the suns rays and could cause severe burns in the user.