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BOOT CAMP 026
PCs & PICTURES PART 2 DIGITAL CAMERAS
Fading, blurred and out of focus pictures first started
coming back from the chemists almost two hundred years ago. The chemists
concerned were Sir Humphry Davy and Thomas Wedgwood, who outlined the basic
principles of chemical photography in the Journal of the Royal Institution back
in 1802.
And so it was until 1981, when Sony unveiled the first
prototype electronic still camera, called Mavica. It used a solid-state image
sensor instead of film and recorded images on a miniature floppy disc. Pictures
could be displayed directly on a TV, sent down telephone wires or printed out
on paper. Electronic still photography finally came of age during the mid
1990's when the first low-cost digital still cameras (DSCs) started to appear.
Digital still cameras still have some way to go to match the
performance and price of film cameras but the pace of development is nothing
short of phenomenal, so what can they do for you? The traditional family photo
album is safe for a while so don't throw away your 35mm or APS compact just
yet, but if you've got a reasonably up to date Pentium PC and a colour printer,
a DSC can be an extremely useful and entertaining peripheral. They're a fast
and efficient way of capturing images, to illustrate documents, newsletters,
presentations and internet web pages. You can use them to create personalised calendars,
greeting cards, PC backgrounds icons, photo identity cards and send pictures to
relatives abroad, in fact any application where you need to get an image into a
PC, the list is endless.
The benefits of DCS photography are many and varied. There's
no waiting for prints to be processed, many current models have built-in LCD
viewing screens so you can compose the shot and check the image straight away,
and if necessary re-shoot. Running costs are minimal, there's no film to buy,
(though some DSCs get through batteries at an alarming rate). Storage capacity
is increasing all the time, DSCs typically capture between 50 and 100 images on
internal memory chips or cards and they can be downloaded onto the PC's hard
disc at any time, to free up space.
Most current models look and work like exactly a compact
35mm camera, and they're just as easy to use, simply point and shoot. DSCs with
manual exposure systems and interchangeable lenses are available too, though
expect to pay for the privilege. Virtually all DSCs come with PC and Mac
connection kits, that include a serial transfer lead -- it plugs into one of
the COM sockets on the back of the PC -- and a suite of operating software. In
most cases that's a capture and photo album utility, for retrieving and storing
images, plus one or more graphics programs. These have templates for calendars,
greetings cards and posters plus utilities for editing photographs, special
effects, correcting faults, like red-eye, colour imbalance and adjusting
brightness and contrast. In short the software gives you the kind of creative
control over your photographs normally only possible in a well-equipped film-processing
lab.
So what's the catch? The two problem areas are price and picture
quality. Budget and mid-range DSCs typically sell for between £250 to £400 but
prices are falling rapidly and industry pundits expect there will be a good
choice of cameras costing £150 or less by Christmas. Theoretically the price
has even further to fall and the first sub £100 DSCs are probably less than a
year away. Of course you have to take into account the cost of a PC and a
decent colour printer, if you want hard copies and permanent storage, but most
prospective DSC owners will already have a computer.
Picture quality on first generation DSCs was quite
poor. Resolution -- the ability to
capture fine detail -- and colour accuracy are mainly determined by the number
of light sensitive picture elements or 'pixels', in the CCD imaging chip. Early
models typically had sensor grids containing just a few thousand pixels (320 x
240 or 480 x 320). The current norm is 640 x 480, which is equivalent to a VGA
PC display and sufficient for most applications but an increasing number of
mid-market cameras are now up to XGA standard, using so-called 'megapixel'
sensors with 1024 x 960 and 1280 x 960 pixel arrays.
The trade-off with resolution is storage capacity but the
cost of memory chips is tumbling too, moreover a growing number of cameras use
advanced compression techniques, such as JPEG, to reduce the size of the image
files, without unduly affecting quality.
Setting up the capture utility on a Windows 95 PC normally
takes just a few minutes. Most camera software is supplied on CD-ROM and uses
Plug and Play to install the programs configure the COM port and establish the
link with the camera. After that it takes just a couple of mouse clicks to view
the contents of the camera's memory. To speed up the process most capture
programs download a set of thumbnail or preview images; this takes just a few
seconds, then click on the images you want to retrieve to load a full-sized
picture. A bitmap file can take up to a minute to download, depending on the
camera and PC. Uncompressed images also take up a lot of room -- several tens
of megabytes -- so you will need plenty of free hard disc space on your PC.
However, it's a relatively simple matter to compress files, using the supplied
software or programs such as PaintShop Pro or MGI Photo Suite (supplied with a
lot of DSC's) which have file conversion facilities.
Some DSCs bypass the serial link connection by using
removable memory cards. These postage-stamp sized modules fit into special
PCMCIA cards, that slot into expansion sockets on the sides of laptop and
notebook PCs; the same modules can also be used in floppy-disc adaptors, that
can be read by a normal 3.5-inch disc drive. A handful of cameras have infrared
communication systems that transmit data to suitably equipped PCs and printers.
However, cameras with IR comms links tend to be part of a single-make system,
and often only work with compatible devices from the same manufacturer.
Megapixel camera performance is getting close to photographic
film -- especially when used in conjunction with the latest photorealistic
colour inkjet printers; it can be good enough for many domestic applications
and if the present rate of development continues film cameras could be on the
way out within five years! See for
yourself, most PC dealers are only too please to give demonstrations. If you're
thinking of buying a DSC, and quality is an issue, then you should shortlist
megapixel models, or wait for prices to come down.
JARGON FILTER
CCD -- charged coupled device, a microchip image sensor that
converts light into digital data
JPEG -- Joint Photographic Experts Group, a sub committee of
the International Standards Organisations, responsible for devising software
compression systems
PCMCIA -- personal computer memory card international association,
now called a PC card, standard-sized module used in laptops for memory
expansion and other peripherals, including modem cards
TIP OF THE WEEK
Thunderstorms are not uncommon at this time of year and they
can be fatal for PCs. Strikes on nearby overhead cables and sub-stations can
send high voltage 'spikes' down mains supplies, frying computers and other electronic
devices. It's sensible to switch your PC off, disconnect the mains plug and
telephone modem lead during a thunderstorm, even if its not directly overhead. If
that's not possible then it is worth investing in surge protection devices, for
the mains and telephone connections. Protection devices, built into mains
sockets or multi-way adaptors are relatively inexpensive -- £20 to £50 --
compared with the cost of PC and loss of data. Telephone line protectors start
at around £40 and are readily available from PC stockists.
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