Megapixels of Doom
There seems to be a file size disconnect between pictures
routinely snapped by most digital cameras, and the desire of
many amateur photographers to share their pics as email
attachments or online.
Photographically, most of us are using an elephant gun to shoot
a flea. We respond like addicts when each camera ad offers to
place yet more megapixels at our disposal, and we brag at
cocktail parties that ours has more than yours. But such are
actions of the uninformed.
In the real world, unless you are a pro, all those pixels are
unnecessary and can bring trouble.
A very average digital camera will take a snapshot which is
composed of 2048 x 1536 pixels (dots). This is called the image
resolution. If you multiply the two numbers, you get 3,146,000
pixels, or dots, which comprise your picture. This is the number
(3.1 megapixels) the camera companies tout as being more
wonderful than sex and drugs taken in unison.
Photos are saved in JPG format, in medium-high compression. The
file size for one photo will be about 2/3 of one megabyte. For
math fans, that works out to 1 kilobyte of storage memory
controlling 2/3 of one square inch of picture.
"So whazza problem? Got my camera, it gots the mega-whatevers,
my chick digs it, evateeng's cool, man. No?"
Not quite, cool dude. Because when you try to email your chick
pics of her fine accoutrements, your email gonna choke after
just a few hot shots. And if you try to upload some of the
better images to www.neighbors-in-labor.com or some such amateur
site, she might look a little diseased after the website
downsizes her.
Why? Because even the biggest typical screen (17"), with one big
picture filling the screen would only use about .8 megapixels
(800,000 dots). If you wanted her picture to display on the
screen the size of a 5x7 photo, that would only use 1/10th of a
megapixel. You shot 3 megapixels too many, sucker!
That's not the only problem. Your mega pictures will choke her
email system and possibly not deliver if you send too many at
once. When you hit "Send", it will take a while and possibly
forever.
If your photo were optimized for screen viewing, your 5x7 photo
would use only about 40 kilobytes (4% of one megapixel!) of
storage memory and would look every bit as good. You could send
a bunch to her and all your friends.
Thus we arrive at the crux. You could share and send 16 pictures
using the amount of memory you used to store a single photo from
your fancy-shmancy camera. But don't feel bad. You are
definitely not the only one bragging at the party.
The solution, by the way, is to find a camera which allows you
to take lower resolution pictures. If you see an art shot you
might want to print out at 8x10, crank the resolution for that
shot only.
For the bloated pictures you already own, get photo editing
software which allows you to downsize the photos while
monitoring quality and file size.
Adobe Photoshop is the big name in this field. When you get good
at it, you can even create a "droplet", a small icon which sits
on your desktop. With Windows Explorer running next to it, drag
the folder containing your fat photos over the droplet icon. The
entire batch will be immediately downsized according to your
instructions.
Now that is something to brag about!