• Thinking of buying some clear resin to see if my u/w magnifying math is accurate: I can 3D print the biconvex lenses, smooth the printing with spray lacquer, and get a sense. It won't be usable quality, I wouldn't think, but the curves aren't insane, even for a material with a lower refractive index.


  • My latest stupid idea is an underwater magnifying glass. Normal magnifying glasses don't work well underwater because seawater has a refractive index of 1.33 and common optical acrylics and glass are only ~1.50. There used to be a company in Belgium that sold an u/w magnifier for around $150 and you had to wait in line to get one, but they seem to have gone out of business. The math is pretty straightforward and so I've put an RFP out on Alibaba.