The world of optics and lens manufacturing has traditionally been closed off to non-experts. It doesn't have to be that way. Using rapid prototyping tools like 3D printers and CNC routers, making a lens is easier than you might think.
You can use the technique outlined in this Instructable to make very large lenses, lenses that produce special effects, and sculptural lenses with freeform shapes. You'll need to know how to use a CNC router or have access to a nice 3D printer. With one of the two you'll be able to start making lenses right away.
I made my first lens while building a projector for a robotic sculpture. I built the sculpture's projector assembly myself and was unable to find a projection lens that fit my requirements. Every commercially available lens was either too small or too expensive. I decided to try making my own lens instead (though I knew almost nothing about optics). I found a hunk of acrylic plastic and used a 3-axis CNC router to mill it into a lens shape. The lens cast a slightly blurry image, but it worked!
Since then I’ve become obsessed with perfecting this technique. I developed best practices for cutting lenses on CNC routers, learned how to print optics on 3D printers, and created a polishing technique to increase optical clarity. Most recently, I used the facilities at Autodesk's Pier 9 Workshop to fabricate a series of face-distorting lenses for a public art festival. I hope that by sharing what I’ve learned I can inspire others to make their own optics.
- How to design a lens using ray tracing software
- A process for 3D printing lenses
- How to make lenses using a CNC router (an alternative to 3D printing)
- My process for polishing printed and milled lenses
- Some ideas for how to use a custom lens