I think these things are ingenious, and also kind of amusing.
It's clear that what some target archers really wanted was a reflex sight, like those used on some firearms, or the red dot finders on some telescopes, or the pre-HUD reflector gun sights in old fighter aircraft, but they're not allowed! The World Archery rules forbid any electric or electronic devices on the bow (no lasers or LEDs for you!), and the rules for recurve bows also ban sights that include any "prism, magnifying lens/lenses, or any magnifying device, level, electric or electronic devices".
So what do you do if you really, really want a glowing coloured dot but you can't have any light sources or optics? You get a piece of coloured "fibre optic" (plastic light guide) and put it in the middle of your sight ring, of course. Some of the ambient light shining in through the side of the fibre gets trapped and is funneled out of the ends, giving you a point of light generated by entirely passive means. It even auto-dims when the amount of ambient light changes!
Some of these just use a short, straight section of fibre held in the middle of the sight ring. The rules allow these to be up to 2 cm long, but the rules also allow longer fibres as long as they bend after 2 cm and exit the line of sight. This sight pin takes that to an extreme by wrapping the fibre three times around the outside of the sight ring to get lots of light gathering length. They're missing a trick by not sticking something reflective on the other end of the fibre though, half of the collected light is pointlessly shining out of the back of the sight. Still, it's pretty bright, brighter than this video makes it look.
#Archery #Optics
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