By Patricia Daukantas
As a high-school graduation gift, I got my first “real” camera – a 35-mm single-lens reflex, rather than a fixed-focus Instamatic for snapshots – and began to learn the artistic joys and challenges of manipulating the depth of field. What, in a scene, did I want to focus on? Sometimes I wanted to keep both foreground and background objects sharp and clear, but I couldn’t, especially when the ambient light level forced me to use a large aperture.
Now, researchers based at the University of Toronto (Canada) say that they’ve developed a new type of video camera that will keep high-resolution near- and far-field images in focus simultaneously.
This “Omni-focus Video Camera” is actually an array of color video cameras that are each focused at a different distance. The images from each of these video cameras are fed into a component invented by OSA Fellow – and frequent OPN contributor – Keigo Iizuka. This component, the “Divcam” (for Divergence-ratio Axi-vision Camera), performs real-time mapping of the distances between the pixels and the objects in the scene. Software developed by another Canadian scientist, David Wilkes, selects individual pixels from all the available camera outputs on the basis of the distance information and puts together a single image that is “omni-focused.”
The researchers say that the camera could have many different applications that could use greater depth of field, ranging from TV studio cameras to laparoscopic medical procedures.
The new camera isn’t commercially available yet, but the university recently announced it to the media. According to Iizuka, who is the principal investigator of the project as well as a Toronto engineering professor, the team last week submitted a comprehensive article about the camera to a scientific journal.
In the meantime, here are a couple of illustrations of the technology (photo credits: University of Toronto).
Above: Comparison between the Omni-focus Video Camera (a) and a conventional video camera (b). Note that the fingerprints are recognizable in (a).
Above: The eye of one sewing needle is captured through the eye of a second needle – 1.17 m in front of it.
2010-05 May, Applied optics, Imaging, Photography