most of his work is under lock and key -as he would be, today- because
his genre was taking nude photographs of pre-pubescent girls (with the
enthusiastic approval of their parents, incidentally). But those were
different times...a more innocent age, and a subject, perhaps, for a
future column on digitally re-creating the look and feel of Victorian
The reason it's the right time to buy your first digital camera is that
the field has begun to stabilize and the distinction between images
produced by a film cameras vs. a digital ones are becoming blurred (no
pun, intended) to the point where you cannot always tell one from the
other. Furthermore, you can now buy some outstanding digital cameras
for between $500 and $1,500, a price range that would have been unthinkable
just a year ago.
Few things are more thrilling than shooting pictures with a digital
camera and then with hardly any steps in between seeing them
splash onto your computer screen and flow smoothly into your image editing
program. It's the same as watching the birth of a photographic print
in a developer tray, or experiencing the chills that accompany unwinding
still-wet negatives from a reel and holding them up to the light.
Of course, if you need a reason, other than being on the cutting edge
of photography, to buy one of these cameras, consider the following
advantages: instant image checking after you shoot, no scanning, no
film costs (which encourages creativity), and promoting a cleaner environment.
Whatever your motivation, this column will acquaint you with the basics
of digital photography. Part 2 will go into details on specific cameras
No discussion about digital cameras and imaging can avoid the subject
of resolution. Simply defined, resolution is the ability of a device
to record fine details in an image...like individual threads in a sweater
or separate grains of sand on a beach. Images from digital cameras (and
scanners) are made up of little squares (sometimes rectangles) called
pixels. Pixel is short for "picture cell" or "picture
A digital camera's imaging surface is made up of rows of tiny
individual light sensors that capture color and light information which
is then electrically converted into digital datathe cells or pixels
that make up the image. If a camera is capable of capturing an image
that consists of 640 horizontal by 480 vertical pixels, it is said to
have a resolution of 680 by 480 pixels or 307,200 pixels (arrived at
by multiplying the two dimensions).
Thee total sensor array is called a charge-coupled device (CCD) and
is used on most digital cameras now on the market. However, some cameras
are being built around complementary metal oxide semiconductor (CMOS)
devices which are more reasonably priced and require very little power
compared to CCD sensors. More about CMOS digital cameras in a later
The more pixels that can be packed into a given area, the higher the resolution
resulting in a finer-detailed image. Think of it as using graph paper
to help you draw a picture. The more squares per inch, the more nuances
you'll be able to capture. Higher is better when it comes to digital cameras.
Buy a camera with as high a resolution as you can afford if you want to
make prints 5" by 7" to 11" by 14". Reasonably-priced
digital cameras are now available in the 800,000 to 1.4 Megapixel range
that will satisfy that requirement.
At this point, I'd like to dispel the myth, perpetrated by photographers
in defense of traditional film-based imaging, that digital resolution
is not -nor can it ever be- as high as film resolution. Wake up! It's
higher. If you don't believe me, ask Kodak. Digital capture is capable
of far more resolution than film...it's just that at this point in time
it's a fairly expensive purchase for the average photographer, exposure
times are relatively long, and the computer files generated are quite
large. But that will change...as does everything in electronics that we
first consider impossible.
But even now, most catalog photographs are being shot digitally with a
special back that fits on most professional cameras. The old axiom that
says you can have any two elements...quality, speed, or economy, but not
all three, has been shattered because the quality is outstanding, the
results can be seen immediately, and the systems pay for themselves in
one to two years...saving huge amounts of money in film, processing, and
re-shooting expenses thereafter.
Lately, specifying digital camera resolution has become a bit tricky because
you have optical resolution (the actual number of sensors in the array)
and interpolated resolution, which uses software magic to kick the optically
obtained image to a higher resolution by artificially adding more pixels.
Some camera manufacturers fail miserably at this, but others, like Agfa,
do a magnificent job and the software process used to do the interpolation
when images are transferred to computer from all but their lowest cost
camera is called, appropriately, PhotoGenie.
I recently shot a picture of one of my cats using an Agfa ePhoto1280 and
printed it at 8" by 10." You can see every hair as well as subtle
gradations in blacks, tans, and greys...and this from an optical resolution
of only 810,000 pixels interpolated to 1,228,800 pixels where about a
third more pixels have been added to the image to increase its resolution.
Agfa claims they're using artificial intelligence which sounds like a
bit of hype; nevertheless it works well.
Click the image to enlarge
Kodak starts off with rectangular cells in some cameras which they then
convert to square pixels. Thus a CCD consisting of 984 by 850 rectangular
pixels is converted to 1280 by 960 pixels. The advantages of this are
a smaller file size (greater storage capacity) and lower cost than offered
by a CCD that is a full 1280 by 960 pixels. The resultant image is slightly
softer in the horizontal direction than an image captured with a CCD that
is a full 1280 by 960 pixels but Kodak says you can adjust for this softness,
if needed, using a third-party, image-editing application.
Of course, if you've used an imaging program you know that you can only
interpolate (or upsample) so much before you begin to lose sharpness.
So like everything else in life, it's a trade-off...although since the
interpolation on digital cameras is not extreme, you probably won't be
unhappy with the results.
The rule of thumb for buying your first digital camera is that it should
have 1,000 pixels or more as one of the numbers describing its resolution.
Incidentally, most cameras offer a choice of high and low resolution modes.
Use the higher one if you want prints, and the lower one for web images
or for sending photos as email attachments.
Is Bigger, Too
Of course, the higher the resolution, the larger the file size
even though most images are compressed in the camera using JPEG (Joint
Photographic Experts Group) encoding. At first, you'll probably want
to save every gem you've shot, so expect your hard disk to fill up fast
(a good reason to buy a removable drive, with plenty of cartridges).
Your file sizes will depend on the specific image and the degree of
compression you choose (user selectable on many cameras).
Figure that an uncompressed image will be roughly five to twenty times
larger than its compressed size. A 640 by 480 pixel image compressed
to 50K will inflate to about 900K when opened in an image editing program.
A 1,024 by 768 pixel image compressed to 200K expands to 2.25MB. And
when you get up to 1,280 by 1,024, a 900K JPEG balloons to 3.75MB. With
some cameras that let you shoot and save uncompressed images, file size
can mushroom to 5.6MB.
That's only the beginning. If you do any editing on images, you won't
want to re-save them as JPEGs, because JPEG is a lossy compression method.
This means that to reduce file size, some of the image information is
lost; once gone, you can't get those pixels back without starting over
from your original image (and always work from a copy, never the original).
So save images in the Tagged Image File Format, (TIFF or .TIF) with
LZW lossless compression, if available, to save space.
To make it simple, bring the image into your imaging program and then,
before doing anything, save it as a TIFF. Then you can begin working
on it and it will always subsequently close and re-open as a TIFF, eliminating
the risk of it being closed as a JPEG and becoming further degraded
if you open it again to do some more work on it.
Is a Plus
The first time I transferred images from a digital camera through a
serial port to my hard drive I was too excited to notice that each one
took about 30 seconds. Doesn't sound like much, but when you transfer
40 exposures, that's a minimum of 20 minutes. Plus, it takes still more
time to rotate those vertical shots upright so you don't twist your
neck out of shape viewing them.
Then, once downloaded, you must separate the good, the bad, and the
ugly. So far, there's no easy way to do this. The "digital contact
sheet" displayed prior to downloading isn't as they say where
I live worth spit. The images are too small and you can't see detail.
So, expect to end up transferring most of them. And when they're finally
aboard, it's not easy to position them side-by-side on the screen without
resizing them and fiddling even more.
All this is changing, of course. You'll soon be able to routinely transfer
scores of images in a flash (literally) and software will eventually
take care of positioning and selection. But for now, prepare to have
your patience tested.
You'll need a photo imaging program to transfer and work with your pictures.
Most digital cameras include plug-ins that you add to the program to
simplify this process. Adobe's cross-platform PhotoDeluxe is bundled
with many cameras. You can also opt for the de facto industry standard,
Adobe Photoshop which, incidentally, after four iterations has finally
added multiple undo-redo in its latest version, Photoshop 5.
While a plug-in is the easiest way to get images out of the camera and
into a program, many digital camera manufacturers are now including
their own stand-alone programs that will allow downloading to a folder
or directory. Some even have limited editing capabilities and, until
you pick the digital imaging program you want to marry (divorce not
being an easy option in this field), you can do a bit of refining with
them and then print out your results.
Unlike conventional cameras where you can select films with different
sensitivities to light, all digital cameras in the under-$2,000 price
range, except one, offer only a pre-set sensitivity to light, usually
a film-equivalent ISO of 50 to 200. It's not a big limitation, though.
Many of them take perfectly acceptable pictures under low light conditions
because their lens apertures are pretty fast, usually around f-2.8.
As a standard feature, most have a built-in flash for really abysmal
conditions and for filling in deep shadows on sunlit, high-contrast
subjects. And when it comes to freezing action, some even have shutter
speeds up to 1/16,000th of a second!
What you may find disconcerting, at first, is the slight time lag that
occurs between pressing the shutter release and the actual exposure.
That's when the camera spends a fraction of a second going through its
pre-shot calibration and white-balancing act. But as a bonus, if you
shoot under fluorescent lights, for example, you'll get perfectly color-balanced
pictures instead of ghastly green ones. There's also some delay between
shots while the camera processes and compresses the image. You'll quickly
adjust to these quirks, though, and things are improving every day...some
cameras can now even take multiple shots per second at their lower resolution
Even the best digital camera will seem like a poor choice if you can't
keep it still when shooting. Favor cameras that have conventional optical
viewfinders or through-the-lens reflex viewing, and look for cameras
you can steady against your head to avoid camera shake. Cameras that
provide only an LCD screen to view the image you're going to shoot may
look nice sitting in a camera store, but they require that you hold
the camera away from you to frame the shot, which creates unsteadiness
and tired arms. Also, the LCD image washes out if you shoot outside
with the sun at your side or back. Exceptions are cameras with viewing
screens that swivel to allow you to look down into them while holding
your elbows relaxed at your side.
Batteries, and Storage Cards
Shakiness aside, cameras that have integrated LCD screens (or as accessories)
in addition to a regular viewfinder are quite useful. They're great
for checking the quality of pictures you've already taken and can help
you pre-frame tight close-ups shots, preferably with the camera on a
Some cameras allow you to view images on a television screen. This is
a handy feature, especially if you want to check a large view of your
shots when you're traveling and don't have a computer handy. You can
also use the camera for presentations by pre-recording your pictures
in the correct sequence on a storage card. Just make sure you buy an
AC adapter if it's not supplied with the camera and remember that vertical
shots will display as horizontals on the screen.
You will need rechargeable batteries and a charger if they don't come
with the camera. Most digital cameras eat batteries like candy, especially
since they must power the flash and the LCD screen used to preview and
post-view shots (if the camera has an LCD). The best batteries for most
digital cameras are QUEST Nickel Metal Hydride (NiMH)...made in the
USA by Harding Energy. I have found that NiMH batteries called "Clean
Cell" from China that are supplied with some cameras have a very
short service life before they need recharging.
Q UEST batteries hold a near-constant voltage when in use and I've found
they last two to three times longer than other rechargeables. Unlike
Ni-Cads (which I detest) you can fully recharge them anytime because
they have no memory problems and they can be recharged with any Ni-Cad
charger you may already own. Although they can take up to 16 hours to
recharge, they are so inexpensive you can buy several sets so you'll
always have enough on hand. If fast recharging is a must, a special
fast charger will be available soon.
Most digital cameras now use removable storage cards but there's no
established standard. The SmartMedia Card holds great promise because
in addition to being able to transfer images directly from the camera
to your computer, it can also (with appropriate adapters) pop into a
PC card reader or directly into your floppy drive for even faster cable-free
downloading. Don't confuse this capability with Sony cameras that use
standard high-density floppy disks; the SmartMedia card is about the
size of a large postage stamp and uses a Flashpath adapter that slips
into your floppy drive.
Image Quality Before You Buy
I also suggest you check out camera picture quality at different
resolutions before you buy. Some camera manufacturers offer sample images
on their Web sites and I'll list the sites in my next column. But if
you're over-eager and beat me to it, make sure you don't print the images
from within your Web browser because your output will be locked at the
screen resolution of 72 or 96 ppi. Instead, download them as files and
then open them in an imaging program of your choice. From there, print
your samples at different resolutions and sizes to see for yourself
how they'll look. It's a great way to see what you'll get before you
Finally, zoom lenses for digital cameras now come in two flavors...optical
and digital. To make matters even more challenging, some cameras incorporate
both. On a digital camera with an optical zoom, the resolution remains
the same regardless of the focal length you choose. But a digital zoom
uses only part of the sensor array -exactly as if you'd cropped the
image- and the resolution drops accordingly. The new Olympus D340L,
for example has a resolution of 1280 by 960, but using the telephoto
mode or the sequence shooting mode produces images that are only 640
by 480. To put it simply, just remember: "Optical zoom, good; digital
zoom, bad," unless you're shooting only for the web or for CD-ROM
multimedia productions, in which case it doesn't matter.
Whichever digital camera you choose, keep in mind that it probably won't
be the only digital camera you're going to own. It's rather unlikely
you're still using a 35mm camera without autoexposure or autofocus.
Even though the future promises better hardware with more features,
while you wait for your ideal digital camera to appear you'll be missing
out on learning how to use this fascinating new photographic medium.
And then there's always the competition...if you wait too long, your
contemporaries will be at ease with digital photography while you're
still looking on from the sidelines. In my next column, to help you
make some informed decisions and minimize "buyer's remorse,"
I'll suggest some excellent choices that will stand the test of time...well,
for at least six months, anyway :-)
QUEST NiMH Batteries
As these batteries are in great
demand, I've listed the four biggest dealers in the U.S. To keep the
price of the recharger reasonable, the red lights don't go out when
the batteries have reached full charge, so keep an eye on the clock.
They won't be harmed, though, if they sit in the charger for long periods
of time, although they'll get rather warm.
Cedar Falls, IA