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 imaging, video, video camera, applied optics, photography, camera, lenses, divcam, image mapping

By Patricia Daukantas

We know Mars as the Red Planet, but what color is its sky? Early Viking lander photos from 1976 seemed to show a light blue sky, but a recalibration—and subsequent images from the Mars Pathfinder mission in 1997—changed the atmosphere to a light pink and then to a butterscotch color.

Such calibration depends on having a handy color-reference target in the field of view of the lander camera. Viking used an American flag, a symbol of the U.S. bicentennial celebration in 1976 (remember that?) and a small color grid, all posted on the outside of the spacecraft. NASA’s Phoenix lander, which touched down successfully on May 25, uses two color-calibration targets specially designed for the mission by scientists at the University of Central Florida.

UCF physics and astronomy professor Dan Britt and two of his students made the color chips, which range from white to royal blue (but no red), to aid spectroscopists in figuring out the true colors and composition of the Martian soil. The targets have built-in magnets to help keep them free of dust buildup, which was a problem on earlier missions.

The UCF team collaborated with a University of Florida chemistry professor and a group from the University of Copenhagen in Denmark. For more information and a photo of the color-calibration target, check the UCF Web site.

2008-05 May, Astronomy, Imaging engineering, imaging, astronomy, camera, spectroscopy, color, calibration

By Patricia Daukantas

The popular rock band U2 made its first concert movie two decades ago. So why are film critics falling all over themselves to rave about its second movie?

The answer, it turns out, lies in optical imaging technology. The directors of “U2 3D,” which opened recently in limited engagement, used special 3D digital cameras from 3ality Digital Inc. of Burbank, Calif., to film the live-action concerts.

As reported by Wired.com, each of the 3ality mobile camera setups—there were nine in all—incorporated two Sony digital cameras, surround-sound recording equipment, and an unprecedented degree of computer control of the cameras and zoom lenses. The cameras generated incredible amounts of data, which fiber-optic cables fed into 3ality’s servers for editing and post-production. (The finished film contains almost 1 petabyte of data—that’s as much as 1 million 1-GB USB drives.)

More information is available on the movie's Web site—but check your computer’s speakers before surfing there, as the home page features Bono’s voice singing the opening of the song “Vertigo.”

2008-02 February, Imaging, Optics and pop culture 3d, optics and pop culture, science rock