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Megapixels of Doom
A humorous and informative explanation of image resolution and file sizes for pictures.
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!
ArticleSource: ArticlesAlley.com
About the author
Mark Meshulam offers the Poingo Productivity Suite, a suite of simple software programs which make your work, including image handling, much easier and more fun. visit http://www.poingo.com
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