Watch a drop of water turn into a camera lens with just some electricity

A water droplet makes a concave shape that works as a perfect lens, particularly when that water droplet is applied to a repellent surface. The droplet and glass plate was added to an set of aperture blades, which allows the photographer to control the camera’s f-stop. That custom lens was set on top of a digital camera sensor for one of the oddest camera constructions yet, alongside lensless cameras and 3D-printed lenses.

While the shape of a water droplet will bend light much like the glass inside a traditional lens, the next problem was tackling a way to focus the image. Traditional lenses use multiple glass pieces to reshape the light, and when the shape of the object meets up with the sensor, the image is in focus. Instead, the researchers used electric currents to reshape the water, which allows the shape of the lens to adjust, altering the focus.

The company, in a cleverly thought out out advertisement, put that water-based camera in the hands of photographer Robin de Puy. The photographer then captured a series of portraits with the water-based lens.

While most photographers try to avoid getting water on their lens, the idea of hacking a water droplet’s magnifying and light bending properties isn’t entirely new. One iPhone photography hack suggests using a water drop instead of a macro lens while the Best Experimental Film from Manchester’s 2016 film festival was shot entirely with a waterdroplet lens. Researchers from the Rensselaer Polytechnic Institute created a water lens that focused with the vibrations from sound waves back in 2008.

While the lens may have been constructed as a way to advertise bottled water, the science behind why — and how — the lens works makes it a fascinating watch.