Visualising Electromagnetic Fields

Luke Sturgeon
Jun 29, 2015 · 6 min read

You can view all of the original images in the Flickr set we created for this project.

Our project is the result of a one week Experimental Imaging workshop at CIID run by visiting faculty Matt Cottam from Tellart and Timo Arnell from BERG. Myself and Shamik Ray worked together to “make the invisible visible”. The purpose of the workshop was for us to experiment with traditional photographic techniques, whilst exploring invisible phenomena in our everyday lives. No retouching or digital manipulation was allowed and every image you see must be captured directly through the lens of a camera. As interaction designers we were expected to research and explore an invisible phenomena and create a suitable visual language to communicate it’s material qualities.

Due to the experimental nature of the workshop, we were encourage to explore technical and photographic techniques simultaneously. The Flickr set and Vimeo video are both presented in chronological order to explain our process and see how each experiment lead to the next. Each time we produced a stop-frame or series of stills, we would critique them, discover a new area to explore and the start a new exploration in a different way.

Initially we explored light and long exposure and how to capture images in absolutely darkness.

Next we downloaded a free EMF Sensor app and installed it on our Android phone. The app measure’s magnetic fields using the phone’s built in sensors. Each single exposure above the laptop involved Shamik holding down the exposure of the camera whilst I carefully dragged the phone around the edges of the laptop. The graph-like qualities of the light are a result of the application’s interface — we cut a cardboard sleeve with a thin slot to mask all but the nine status lights. During these photographs we were experimenting with exposure time, movement, flash exposures and lighting — all within a single exposure. The outcome was a series of stills and two stop-frame animations (both animations have nearly 200 single exposures that took 45 second each).

Learning from the first set of animations we quickly created our own Android application, written in Processing and uploaded to the phone. I’ve uploaded the code to Github and it has already helped other people to learn and explore magnetic fields in their own projects. With this application we created our own tool for drawing with light and EMF, so the next set of photographs involved us learning how to use the tool, which was a white shape that grew in size based on the strength of the magnetic field. We experimented with different colours to signify intensity as well as shapes and gestures. We also invited other people to play with our tool and experience painting for themselves, it was a fun experience as every exposure revealed different and unexpected results. After a few hours I had familiarised myself with the “light-brush” and could paint certain shapes, for example drawing circles meant that the left and right edges because thicker during the long exposure, so I learnt to vary the speed that I moved my hands so that we could create a smooth and consistent density of light during the exposures.

The first object was a laptop (the EMF came from the hard drive, CD drive and small motors which produce) and the second object was a small radio (the EMF came from the speaker only). We did experiment with other other devices such as phones, cables and magnets but these were primarily used to help us learn and calibrate our tool. For example the magnetic field values from the speaker ranged from 300–700 whereas the hard dive went from 600–2000+ and would actually cause the phone sensor to pause because the magnetic field was too strong. We’re still not sure what the unit of measurement is for these values but they were the values we received directly from the phone’s magnetic sensor. Our Processing application feature’s a simple set of sliders that allowed us to adjust the sensitivity and ranges in real-time.

We still intend to continue to develop the application and our explorations. We would like to define a suitable and consistent visual language that can be used to measure and compare any type of object that emits a magnetic field.

To produce the images and animations we initially spent 5–6 hours during the each day experimenting with new ideas for light, time, equipment and technique. These initial explorations resulted in the single images that are features in the Flickr set. Once we were happy with the outcomes and understood how to use the setup to paint and discover we would start to capture individual frames for our stop-frame animations.

Initially we created animations that were 12fps, then 18fps and eventually the final animation (the rolling wisp across the surface of the radio) was captured at 24fps. This involved slowly moving the phone over an electronic device, waiting for the long exposure image to process, and then viewing the outcome. This slow and careful process relied on the perfect balance of ambient lighting, flash lighting, exposure time, ISO rating, movement and gesture in order to great the best exposure. The gratification that came from capturing each exposure reflects the similar experience in dark-room photography, slowly watching each photograph develop.

After some configuration and practise, capturing each frame involved:

  1. Me: putting the phone above the object in the correct position and covering the screen with my hand
  2. Shamik: opening the camera’s shutter
  3. Me: quickly removing my hand and slowly dragging the phone across the object’s surface
  4. Me: quickly covering the phone’s screen at the end of the movement
  5. Shamik: manually exposing the scene with a flash
  6. Shamik: releasing the camera’s shutter
  7. Shamik: winding the dolly and moving the camera 2mm
  8. Me: moving my hands down by 2mm and putting the phone above the object in the correct position and covering the screen with my hand.

After many hours of practise this process eventually took around 60 seconds to capture each exposure and move the camera. The project involved many hours under the CIID building in a completely blacked out room in total silence. Physically it was challenging as we were both bent over a table in a blacked out room for 3 days, but we were so excited about the images we were creating that we didn’t pay much attention anything except the results from the camera.

Writing our own application and creating our own tool for expression became one of the most crucial things during the project. We already have experience using Processing and used the Ketai library to access the magnetic sensor on a Nexus 4 Android phone. With these readings from the magnetic sensor we created a Processing sketch that could visualise the values in an abstract way. After some experiments we added ways to reconfigure the sensitivity and behaviours within the application as well as smoothing the results slightly to improve the performance and responsiveness.

One of the great things about this project was the iterative design process we used throughout the workshop. Every experiment lead to several new ideas and instead of dismissing or filtering some of these ideas we were eager to explore every option to see what the results would be.

Technically we were surprised by the difference in magnetic strengths between objects and how strong the electromagnetic field is around hard drives and laptop computers and mobile phones. All of which we live in constant close-proximity to every day.

Another surprise — which came from developing our own tools — was how intriguing and beautiful a single shape can be. By removing as much visual complexity as possible we created an organic form that has appealed to many people who’ve seen the project, and can still be read as an indication of measurement.

We have been very fortunate to have this project featured in the following publications:

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