Dew Drop Lens — Grass Blade Image Inversion

Description

A water droplet on a hydrophilic surface forms a plano-convex lens — flat on the bottom at its contact surface, curved above — with the curved surface creating a real image of the scene behind the droplet according to standard lens optics. The focal length of the droplet lens depends on its size and the radius of curvature of its upper surface, and for droplets in the 2-5mm size range on grass blades, the focal length places the image at approximately 1mm behind the droplet’s rear surface — within the droplet itself, or just beyond, making the image visible within the droplet from the front. This image captures a 3mm dew drop on a grass blade at 3:1 reproduction, the droplet containing the inverted real image of the garden scene behind it: sky at the bottom of the image within the droplet, the distant trees at the top of the droplet’s interior image, forming the characteristic upside-down world within each dew drop.