Through my lens: DIY Plastic lens-hood for Industar-69 28mm f2.8 Lens
DIY: Make Your Own “Lensbaby” Bellows Lens – Photoxels
Amazon.com: Optical Part For 2PCS Optical Plastic Solar Condensing Fresnel Lens DIY 7 Inch Projector Lentes Focal Length 185 120mm Concentrator Lenses (Diameter: Type C) : Electronics
Optical Part For 5PCS 35-49.3mm Optical Plastic Focal Length LED Plano Convex Lens DIY Condensing Lens (Diameter: 40mm F23mm) - - Amazon.com
One Small Step For Magnification, One Giant Leap For Home Lens Manufacturing | Hackaday