Pixels are the building blocks of the digital image world. They
are they tiny picture elements
(hence "pixel") that replace film in digital cameras. The more of
them you have, the greater the potential you have for detail in a
picture. Think of a mosaic picture; the more tiles there are in the
picture, the more detail it can contain.
Camera pixel sensors come in an x-y grid that record the amount
and color of the light in a scene. We can count the number
of pixels horizontally and vertically on
grid and come up with the total number of pixels a camera has by
multiplying one number by the other.
The total number of pixels a given camera has is usually referred
to as term "Megapixel" has become the standard by which the "resolution"
(or number of pixels) of a camera can be measured. For example, a
camera that has 1640 pixels by 1260 pixels would have 2,066,400 total
pixels, or just a shade over 2 Megapixels (Mega means "million").
The greater the number
of pixels a camera has, the larger the image it makes can be enlarged
before the image's pixels can be seen. When we can see the pixels
that make up the image, we say the image is "pixelated."
The table below gives
a sense of how many pixels you need to make a print of a certain
size. This is a good place to start looking at how many megapixels
you might want your new camera to have.
Maximum Print Size
This table often surprises people, as they assume
that when it comes to Megapixels, "more is better." The fact is,
though, that most people don't need nearly
as many megapixels as they think they do. New
York Times Columnist David Pogue recently did a demonstration asking
people to compare prints made from images made with varying number
of pixels. Most people couldn't tell the difference between large
prints made with the different files. You
can see his article here.
you know that you will never need to make a print larger than
5x7 inches, then you also know that you won't need to have
a camera that goes beyond 3 Megapixels. Generally, 3 to 5
Megapixels is enough for most casual photographers.
to keep in mind when thinking about pixel count is the concept
of "cropping" a photograph. When a photograph is cropped to improve
its composition or to zero in on the image information that's
most important to the viewer, we are removing parts of the image.
When we crop a digital photograph, we are removing pixels, so
our total pixel count in an image goes down, so it can't be printed
as large as it otherwise might be able to be.
image as an example:
in mind, if you think you'll be doing a lot of cropping of your
photographs, you may want to consider buying a camera with a
few more pixels than is suggested in the chart above.
this a tough one! There are so many, many cameras on the market
and so many variables of features, price,
storage media, etc. that choosing the "right" one for your
needs is difficult.
I recommend looking at the cameras from Canon, Nikon, Olympus
and Fuji, as they almost always come out on top (usually in the
given them above) in
any kind of testing in digital imaging publications, websites, computer
magazines, etc. A casual poll of students in the Photography
Program at College of DuPage (where I teach) reveals that about
65% of our students use Canon cameras. Canon seems to have captured
the "mind share" in the digital camera world.
best advice I can give is to send you to both of these
them have a really neat feature: They have a "Buyer's Guide"
where you can do a comparison of cameras based on your needs and the
Both sites' guides
offer a sort of “double-blind” sort of a set of questions.
You keep answering questions, and behind the scenes, they
keep narrowing down the “list” of cameras that come closest
to the features you “request” as
you answer the questions. Eventually, you get a short list
of 4 or 5 cameras that come closest to your needs. It's pretty cool and
extremely useful in helping you figure out what you want.
They also have
little links that help define various digital camera terms so you know
what the site is asking you to decide upon as you answer the questions.
Some things to keep in mind as you shop for a digital camera:
Power - Digital cameras are notorious for sucking
up batteries. Make sure that the camera you choose uses a rechargeable
(or can use consumer-supplied rechargables) so you can keep
shooting. If you plan to shoot a lot of photographs or are going
on a trip, you may want to purchase an extra rechargable battery
for your camera so you don't have to stop shooting if you run
out of juice.
Storage - Digital cameras
have to use some sort of storage media on which to save the pictures.
The bigger the
card, the more images
you can store. Popular types of storage are cards called Compact
Flash and Secure
Digital.These are widely available. Some
cameras use proprietary media (Sony's "Memory Sticks" come
to mind). Be careful that you don't choose a camera that uses
method that is hard to find replacements for.
Something to keep in mind
here is that, while you can get a bigger memory card, it might
be a lot more economical to buy 2 or even 3 smaller memory
cards. Not only might this be cheaper, but since memory cards
"fail" from timet to time, you might also find that having
your photographs spread over a couple of memory cards is safer,
Connectivity - Connecting your camera to your
Macintosh or Windows computer allows you to download your pictures
from the camera to the
computer. Check to make sure that this is a process that will
be easy and painless.
Most cameras use cables that go between the camera and the
computer. A nice option is to be able to take the memory card
out of your
camera and put it into a special card reader that mounts the
card on your
computer's desktop much like a hard disk. This method usually
allows for faster transfer, and it saves the camera's batteries,
Zoom, Part 1- Digital Zoom vs. Optical Zoom - We
can't always get close enough to what we want a picture of. This
is where zoom lenses come in. Make sure your camera has
at least a 3x optical zoom. Many cameras offer something called "digital
zoom" which is a poor alternative to a true optical zoom.
Digital zooms simply crop your picture in the camera to remove
edges of the image, making your picture seem bigger. The problem
is that they are cropping away pixels while they do it, so
the resolution and sharpness of your image is usually decreased.
Zoom, Part 2 - Focal Length of Lenses - Another
issue is focal length of lenses (usually expressed in Millimeters
or "mm"). With digital cameras, only the most advanced (read:
expensive) cameras have "full-frame" sensors;
meaning that their sensors are the same size as the 35mm
film frame. Most cameras have lenses that are quite a bit smaller
than a 35mm frame, so the focal length of any lens you put
on the camera will be longer (more telephoto, less wide)
than what you would normally think it would be because the smaller
sensor captures less of the lens' projected image. In other
words, it sort of "crops" the
image from the lens. So, the 28mm focal length of the 28mm
to 105mm might not be as "wide" as you might want, as it
will be closer to a "normal" (or middle) focal length than
you are used to, and you may want to consider a zoom with
shorter minimum focal length. On the other hand, if you prefer
using longer lenses, then it would be a good choice. Another
way to think about it would be to go with the 28 to 105 and
then, at a later time, purchase a short, single-focal-length
Support - It's a really good idea to look at
where you'll get support for your camera, both from the manufacturer
who made your camera
and from the retailer who sold it to you. Take a look at your
preferred camera manufacturer's website to see if it can help
you answer questions
about your camera. Also, the retailer you bought your camera
from can be a very valuable resource. Make sure that they can
understand the intricacies of your camera as well as provide
any needed accessories and services that you may need later.
This is one of the reasons I usually recommend a local retailer
rather than a mail order or "big box" store; it will be a lot
easier for you to get a knowledgeable and concerned salesperson
to help you with post sale problems at P.J.'s
Camera than at
One of the sure things about this is that, since this is a rapidly
changing technology, no matter what camera you choose, it will be
replaced in short order by one that is better and cheaper. That's
life in the 21st Century!
How to Use Your Camera
So, now that you've got it, how do you use it?
There are several options here:
Read the manual! There is no substitute for spending an
hour or two with your camera's manual and revisiting it
from time to time. Push the buttons and find out what they
Take LOTS of pictures! The best part of
digital photography is that taking lots of pictures doesn't
cost anything. It's the best way to learn
Look at LOTS of Pictures! A
basic concept here is that aside from the general operation
of your particular camera's buttons, dials and switches, "photography
is photography" whether it's digital or film-based.
Looking at photographs that interest you and figuring out
what it is about them that makes them good is an important
part of learning to make better pictures.
Take a course! Many community colleges have courses in
of DuPage (where
I teach) has extensive coursework in photography.
Your local community college may offer similar classes.
Attend a Seminar! You might look for
a course at a local camera store, as many of them have
classes that teach basic digital photography concepts.
What's "Red-Eye" and How Can I Get Rid of It?
One of the biggest problems in taking pictures of people with consumer digital cameras is the phenomenon of "red-eye", which often makes the subjects look like they are, well... evil people from the Planet Zircon.
What is happening is that the flash's light is refecting off the blood on the retina of the eye, so the red we see is blood (ick!). Since we're taking pictures of people in "dark" conditions, their irises are open to deal with the dim light, making it easier for the flash to "reach in" and reflect off the back of the eyeball. The closer to the lens the flash is, the more likely it is that you'll get red-eye in portraits of people.When shopping for a camera, one of the things to look for is the greatest distance between the flash unit and the lens. The bigger the angle between the direction of the light and the lens' viewing direction, the less your chances of red-eye are. Problem is, that as cameras get smaller, the flash unit and the lens get closer to one another, not farther (ever notice how pro photographers, like those you might see at a wedding, have their flash units mounted WAY up high on an arm? Guess why).
Most digital cameras (in fact, most consumer-oriented film cameras, too) have a "red-eye reduction" feature. This usually does one of two things: either it fires the flash in a "disco-strobe" mode prior to firing the main flash exposure or it shines a "flashlight" sort of light at your subject for a few seconds prior to firing the flash. As you might guess, this is intended to close down the iris so that the red-eye isn't as pronounced.
Aside from the red-eye reduction features on a camera, things you can do to reduce red-eye are involve moving the subject into brighter light so the iris of the eye closes down a bit, or having the subject look away from the camera, as there is less of a straight path to the retina that way.
There are software solutions to removing red-eye after the fact, as well. Probably the most popular is Adobe's Photoshop Elements, a consumer version of their industry-standard Photoshop application. Photoshop Elements is often bundled with scanneras and sometimes with digital cameras.
For more information on red-eye and solving your problems with it, see this page: Red-Eye Control
How can I make my digital photos look better?
Whether digital or analogue, photographs don't always portray the colors and brightnesses in the world the way we'd like them to. Professional photographers have long used a variety of "post-capture" methods to adjust the visual qualities of their photographs. In the past, this required extensive skill, expensive equipment and a photographic darkroom. One of the big advantages that digital photography has is that using a reasonably-priced computer and inexpensive software, photos that are too dark or have tilted horizons or have "off" colors can be corrected.
While the "Industry Standard" software for manipulating digital photographs is Adobe Photoshop (about $600), for most amateur photographers, that software is overkill. There are several other products that do the job more easily and cost a lot less money than the "high-buck" Photoshop.
Charles Maurer from the website/e-newsletter TidBits has written a great article about how to fix common digital photo problems using inexpensive software, including Adobe's Photoshop Elements, a "stripper" version of Photoshop that is surprisingly powerful and that is available for Macintosh or Windows for well under $100.
See Charles' article here.
Digital pictures are great because they are so
easy to email, put on web pages and look at on your computer's
screen, but what if you want to print them?
Print Your Own
Industry experts tell us that about 78% of all
digital photo users print their own pictures. With inkjet printers
like Epson, Canon and HP becoming
cheaper and better all the time, that's not surprising. Some
printers even allow you to
put your camera's memory card right into
the printer itself
without even having to put the pictures into your computer
There are other options for printing your pictures,
though, offering high quality, great convenience and even potentially
lower cost than printing your own images.
Use a Local Retail Store
One possibility is to use a local camera store or "minilab" retailer.
Almost all of them now have the ability to take nearly any
image storage media (Compact Flash, SmartMedia, CD-ROM, etc)
and make prints from them on regular photographic paper. Some
places even allow you to do some of the editing (cropping,
color adjustments, etc) yourself on a video screen before the
print is made. Alternately, you can leave the "tech" parts
up to the store technician. Retailers like Sam's Club, Walmart
and Costco are places where you can get this service, too.
Use an Online Printing Service
Another option is to use an online printing
service. These are companies that allow you to upload your
digital photos to them over the web and they mail you prints
in a few days' time. Very convenient!
Among the most popular are:
Ofoto and Snapfish
You may find that some of the above choices exist in hybrid
form. That is to say that some local retailers offer the
service of allowing you to upload your photos to them and
then you pick them up in the store. In the town of Glen Elllyn,
Illinois, where I work, the local camera store, PJ's
does just that.
Other examples of hybrid printing services are
software applications for your computer that allow you to organize
and store your images and then upload the ones you want through
that same application. Software like Apple's
iPhoto ( a free application from Apple) is a good
example of this, as is Adobe's
Album software ($49).
Image Permenance & Archiving
"How permanent are my digital images?" is another question
that I get freqently.
The answer is... "it
depends on what it is you mean when you say "images."
Are you talking about the prints or the digital
files themselves? Newer inkjet printers have significantly
increased the life span of an inkjet print. Some printers (primarily
those from Epson) are now claiming 200+ year fade resistance,
depending on the media used (hard to argue with, I guess, for
the obvious reasons).
Older inkjet printers are pretty fugitive
with regard to color permanence and really can't be trusted
in terms of long-term fade resistance.
If you get prints made
at someplace like a camera store or Wal-Mart or Costco, they
are actually imaging the photographs on traditional photographic
paper, processed chemically the way a print from a negative
is processed, so they have the same permanence that you'd get
if you'd shot film and had prints made. That permanence is "pretty
if the images are stored correctly (in archival materials and
away from heat, humidity and light) they should last a long
time. The problem with *any* photograph, digital or
film-based is that the color is made with dyes and colored
dye isn't permanent (think of fabric in your house that gets
hit by the sun every day).
The digital files that you make
when you shoot digital photographs are a different story, mainly
because it relates to how computer technology changes and in
the media we store images on. First off, think of floppy disks.
A format that was pretty much everything 5 or 10 years ago
and now is pretty much gone. Before the 3.5 inch floppies,
there were 5 inch ones; try to find a 5-inch floppy drive today.
If you had your images on 5-inch floppy disks now, you'd be
stuck and it would be pretty tough to get those images off
of those "archaic" floppies.
So, the question is whether the
CD-ROM disks that we can "burn" today
will be something that will be readable in the future. Both
because the technology of CD-ROM will likely change (notice
how burnable DVD is starting to take its place) and also because
the CDs themselves (the actual media) may not be readable in
the future because of failure of the media.
So, even if we
have CD-ROM drives in the future, the CDs we have now may
fail before we can read the data on them. Keeping images on
a hard drive works, but hard drives are basically only sophisticated
magnetic devices, and magnetism isn't always a permanent
Your best bet to save your photographs? BACKUPS.
Lots of backups. The more backups (on varied media) you have
of that precious data, the more likely you are to have the
images you want into the future. Remember that a high-quality
print of the images you most want is a (good) form of backup.
I hope this page has helped you toward a better
understanding of how to make your foray into the world of digital