Lensing Effect
At room temperature, water droplets attached to any surface are not spherical enough to see lensing effect. However, when the temperature gets dropped and reached near the freezing temperature, then the water droplets become an icicle which has elongated shaped like a cylindrical lens. It also has good spherical geometry at the bottom, which helps it to form nice image. In the current picture, the inverted image of the apartment and tree is formed.
—Pravin Vaity, Department of Microsystems Engineering (IMTEK), University of Freiburg
