This rather lovely film was directed by the agency friend and collaborator Timo Arnall and launched at the Cognitive Cities Conference. Timo worked with us on our Light Painting and Media Surfaces films and helped to develop the light painting technique with BERG, so we're really pleased to see the results of his latest explorations. He has now turned his attentions to how the light painting technique can be used to manifest 'unseen' networks in the city.

Working as part of the YOUrban team at the Oslo School of Architecture and Design, Timo's new film reveals the invisible terrain of WiFi networks in urban spaces by light painting signal strength in long-exposure photographs. Having been wowed by the film at Cognitive Cities, we followed up with Einar Sneve Martinussen from YOUrban to find out a bit more about the background to the project.

DL: Can you please explain a little about the background to the project and how the idea for WiFi light painting came about?

ESM: Over the last few years we have been working with designing and developing techniques for revealing invisible technological phenomena. Previously we have worked with the material qualities of RFID as a part of the design research project Touch (based in Oslo) and together with BERG. We visualised the readable volumes of RFID tags and readers and created the film 'Immaterials: Ghost in the field'.

We then moved up a scale and into urban contexts; we started researching the phenomena of networked cities and urban computing in a project called YOUrban. Cities are filled with intangible and immaterial phenomena that are starting to influence how we understand and use our surroundings [such as invisible WiFi networks]. We wanted to use tools and methods from interaction design to reveal and discuss this electromagnetic terrain of networks, and illustrate how it is becoming a part of urban life.

DL: Did you work with any collaborators on the project?

ESM: Immaterials: Light painting WiFi comes out of our previous collaborations with BERG, and explorations of what BERG's Matt Jones has summarised as 'immaterials'. We have wanted to lightpaint WiFi ever since 2009 when we worked with Jack Schulze [also at BERG] on the RFID project. Jack has been important in developing the ideas behind the WiFi visualisations, but because of the scale and time involved in these light paintings we have actually created them in-house in Oslo.

Our team consists of Timo Arnall, Jørn Knutsen and myself, and we did all the building, programming and photography ourselves.

DL: What were the specific challenges you had to overcome (apart from the freezing Oslo winter)?

ESM: The most challenging aspect of the project was to design an instrument that not only visualises WiFi, but works well for light painting. We wanted to gather signal strength information as fast as possible because of the limited exposure times. Ordinary WiFi systems are made for connecting to a network and using it for communication, and only scans for new networks when the connection is lost. To get up the speed of scan-cycles, we were not interested in communication, and instead forced the WiFi module to continuously scan for networks without attempting to connect.

DL: What do you think are the political/social or even commercial possibilities are for this technology? For instance, is this a tool that could be visually used by architects/networks to optimise wireless connection across entire buildings or streets?

ESM: In a political, social and cultural context, the WiFi visualisations can be seen as an attempt at communicating about the networked city to a broad audience. There are great possibilities in, and perhaps a need for illustrating the widespread introduction of networked technologies into cities in a visual language that focuses on the material, spatial and contextual aspects of these technologies.

In a commercial context, I think there is a potential for providing products and applications that allow ordinary people to explore and visualise immaterial technological phenomena in and around their own homes and neighbourhoods.

DL: Can you please tell us a bit about how you achieved the photographic effects?

ESM: Timo Arnall was in charge of photography and is responsible for capturing all the weird photons in our projects. In this project we wanted to create a body of high quality urban landscape photography that would allow people to immerse themselves in the visualisations and the surrounding environment, so Timo spent a great deal of time with different cameras, lenses, ND filters and different exposure times.

DL: Usually we expect the WiFi signal to be stronger near the WiFi access point and weaker if you walk further away from it. From your images instead it looks very irregular, and it's not really matching our expectations. Can you explain a bit about why you think this is?

ESM: When WiFi is spread into the environment it is shaped by architecture, building materials and the urban landscape. Sometimes, using our visualisation, domestic networks from the top floors of buildings flow through several windows then end up as irregular patters at street level. But — more importantly — WiFi zones are not bubbles. They don't have clear edges, but rather a fuzzy belt of random crackle along their perimeters. In short, WiFi networks can be as messy and varied as everything else we encounter in the city.

Einar has also written extensively about the build of and philosophy behind the project. With thanks to Riccardo and Chris at the agency. Vimeo and Flickr content courtesy of YOUrban.