Perhaps it is best to describe Ralf Jacobs as a photographer. He ‘writes with light’ in a wonderful spectrum of old and new techniques, from 19th-century cyanotypes to software-guided laser projections. Combining different photographic procedures and images, he creates new realities that incorporate time as a tangible presence. 


An old-fashioned harmonograph is a machine with rods and weights that mechanically moves a pencil across a piece of paper. Driven by the swinging motions of two or three pendula, it produces an endless variety of intricate elliptic line drawings. Jacobs uses software that emulates these motions instead, to create digital versions. It allows him to tinker with variables like frequency and phase, until a pattern emerges that shows the beauty of scientific imagination, liberating it from its mathematical equations.


A laser can trace the harmonographic image on chemically treated paper to create a cyanotype, a photographic printing process also known as blueprint, discovered in 1842 by Sir John Herschel. Jacobs uses this vintage process also to transfer conventional photographs to the characteristic cyan hue, saturating the image with a melancholy passage of time.

The invisible world

In a next step, superimposing harmonographic images onto regular pictures in cyanotype, Jacobs presents the patterns as alienating elements. Or are they intimate reminders of all that goes on beyond our everyday perception of reality? Another set of mathematical equations that Jacobs explores for their intriguing visual representation belongs to chaos theory. Lorenz attractors, for instance, appear in several of his works, introducing an unpredictable dynamic that seems to suit our era.

Light flukes

The process Jacobs calls light flukes is closest to his profession as an optical engineer. Based on the technique of refractography, it involves a bundle of red, green and blue light that travels through a refractory object, like a glass object or a lens shape, before it is registered by the camera. The resulting colourful chance patterns and images deny their tiny scale to suggest playful forces of a cosmic dimension.


The light phenomena captured by Ralf Jacobs in their appealing complexity and poetic beauty suggest an enviable innocent sense of wonder about the world. Jacobs has retained the ability to be mesmerised by rays of light and their intricate behaviour, even when his profound expertise in optics, lenses and perception might go a long way to elucidate the physical principles behind them. These principles can’t, of course, explain why the images constantly generate new questions and ideas, nor why Jacobs’ photographs can elicit such emotion and meaning.

By Nanne op ‘t Ende, 2022