One day, a video and still camera may be wrapped around car bumpers, lampposts, furniture, clothing and even like wallpaper on a wall! A thin, flexible sheet camera, as thin as paper or fabric may take on the shape of any item it’s attached to and may take photographs and videos from angles previously thought impossible. Any surface may become a camera.
Researchers from the Computer Vision Laboratory at Columbia University have created a flexible adaptive lens array that may one day lead to bendable cameras. Developed of elastic material, it allows the focal length of each lens to vary with the curvature of the sheet. This feeds images into a camera.
Shree Nayar, professor of computer science at Columbia University, along with colleagues T.C. Chang, postdoctoral researcher Yanghoo Yue and research engineer Daniel Sims have been able to create a flexible lens array without losing some of the light-capturing ability in between each sensor as the material bends, a problem with previous attempts. Sims will be presenting this research at the International Conference on Computational Photography at Northwestern University in May.
Cameras today capture the world from essentially a single point in space. While the camera industry has made remarkable progress in shrinking the camera to a tiny device, we are exploring a radically different approach to imaging. We believe there are numerous applications for cameras that are large in format but very thin and highly flexible.
The team created a prototype lens array in several steps. First, they crafted an aluminum mold. Next, they poured in silicone rubber to create a base and cured it in an oven. After peeling it off, they attached a flexible plastic sheet layer with a grid of apertures and a diffuser that can be bent to adjust to the desired focal length. To test it, they positioned a Nikon D90 under a vice that flexed the sheet. The photographs captured were a bit diffuse. The system did prove, though, that the field of view increased the more the lens array was flexed.
The adaptive lens array we have developed is an important step towards making the concept of flexible sheet cameras viable. The next step will be to develop large-format detector arrays to go with the deformable lens array. The amalgamation of the two techniques will lay the foundation for a new class of cameras that expand the range of applications that benefit from imaging.
One goal is to create a flexible sheet camera the size of a credit card that can take a photograph on one side and display the image on the other.
Nayar sums up,
If such a cameras can be made at a low cost (ideally like a roll of plastic sheet), they can be used to image the world in ways that would be difficult to achieve using one or more conventional cameras.