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GRAVITY has a lot to answer for—but until now, few thought it was a
problem for photographers. But engineers working for Fuji in Japan have decided
that digital camera makers have been ignoring gravity’s effects on photos for
too long.

Fuji spent three years analysing a wide range of photographs and saw that
most natural and artificial objects are replete with vertical and horizontal
lines. A spokesman told ¿ìè¶ÌÊÓƵ that Fuji believes this is
largely due to the way natural features such as the horizon on the sea, cliffs
or trees, and parts of our built environment are fashioned by gravity or
designed by humans to oppose gravity. So they reasoned that if they can boost
horizontal and vertical camera resolution, pictures will look better.

But the sensor chips used in digital cameras have until now been best suited
to capturing diagonal lines. So Fuji is now changing the shape and angle of the
elements in its camera sensors to allow digital cameras to take sharper pictures
in lower light.

Digital cameras have a conventional glass lens which focuses the scene to be
photographed onto a flat sensor called a CCD. This contains a matrix of tiny
photodiodes that convert light from an image into electrical charge, which is
digitally coded and shunted off to a memory chip.

Each photodiode represents a pixel in the picture and modern CCD chips in
stills cameras cram two million pixels onto a rectangular chip. If the
photodiodes are made smaller, to make room for more and increase resolution,
they collect less light. So the camera can only be used in bright sunlight or
with a battery-draining electronic flash. The practical size limit for a
conventional CCD chip is around 3 million pixels.

The horizontal alignment pattern of the CCD pixels creates linear gaps in
which horizontal and vertical detail is lost
(see Diagram). Because still
picture cameras—unlike video cameras—are not tied to TV line
structures, Fuji’s new Super CCD can use photodiodes which are octagonal,
arranged in a honeycomb mosaic along 45° diagonals. This allows larger
diodes to be packed closer together, with no linear gaps to lose natural
detail.

The larger diodes gather more light energy, so they need less ambient light
to take a picture. The first Super CCD chips have a high
sensitivity—equivalent to photographic film with an ASA rating of 800. The
honeycomb arrangement gives the 2.5 million octagonal pixels an effective
resolution of 4 million rectangles.

Super CCD debuts in Fuji’s new FinePix 4700 camera, at around £700.