Future for digital snapshots looks crisp 

 Although digital cameras provide both instant gratification and computer-ready images, conventional cameras still make sharper pictures. That crucial advantage of film cameras may, however, be going the way of flashcubes.

 Dutch researchers have developed a prototype image sensor on a chip that produces a picture whose quality rivals that of 35-millimeter film, they say-at least for black-and-white. They packed 6.2 million sensing cells onto their device by shrinking each cell to 3 micrometers (mm) on a side. The chip measures 11 mm on the diagonal, which is larger than typical commercial chips.

 By decreasing cell size and increasing chip area, "we can obtain the quality of standard film," says Herman L. Peek of Philips Semiconductors Image Sensors in Eindhoven, who led the chip's development. The densest arrays now used in commercial digital cameras have 3.2 million light-sensing cells, each 3.5 mm on a side, on a chip measuring 9 mm diagonally, he says.

 Peek and his colleagues unveiled their new technology Dec. 8 at the International Electron Devices meeting of the Institute of Electrical and Electronic Engineers in Washington, D.C.

"To make pixels that size and to make 6 million of them, that's a pretty good feat," says Robert K. Reich of the Massachusetts Institute of Technology's Lincoln Laboratory in Lexington.

 By adding minuscule filters and microlenses to the chip, the group intends to make the chip suitable for color photography. However, tests at Hewlett-Packard Laboratories in Palo Alto, Calif., show that such modifications reduce resolution by about 25 percent, says Hewlett Packard's Rick Baer. The Dutch researchers intend to regain that resolution through future improvements, Peek adds. For now, they compose color photographs by overlaying images shot through external filters.

 Electronics designers usually show their prowess by putting more components into an ever-shrinking area. However, carpeting a larger chip with tiny components presents its own challenge, Reich says. A larger area can harbor more performance-wrecking defects. Over the years, the Dutch group has refined its fabrication methods, culminating in this imager, Reich says.

 Jim Sturm of Princeton University predicts that the time is not far off "when we won't have to use old-fashioned film for very-high-resolution images."