TWO American companies this week demonstrated prototype digital cameras that
can capture much sharper pictures than are possible with a standard film-based
camera. The snag is that the memory needed to store the pictures could be
prohibitively expensive.
Each frame of a 35-millimetre film has billions of silver halide crystals
that are chemically changed by light when the camera’s shutter opens. A digital
camera records images using a mosaic of sensors that convert light into a
digital signal that’s stored in a memory card.
The best sensors today have 3 to 4 million pixels. But even at this
resolution, individual…
