When I wrote a short primer on HDTV a couple of weeks ago, the response convinced me that this is a great time to review the technologies that are most likely to find themselves gift-wrapped this year.




Although digital cameras have been around for a decade now &

and many buyers are on their second or third &

I still get lots of questions about them. So here's the 2007 holiday version of Digital Cameras in a Nutshell:




Instead of using film, digital cameras record images on a grid of light-sensitive dots, usually a charge-coupled device, or CCD.




Once it records an image, the camera stores it on a flash memory card. A typical one-gigabyte memory card can store hundreds of photos. Most cameras have a liquid crystal display (LCD) on the back that allows you to frame shots, review photos stored on the card and erase bad pictures.




You can transfer photos to a PC by connecting the camera directly with a USB cable, or by inserting the memory card into a reader built into the computer. On the PC, you can touch up and crop each photo, then print it directly, transfer it to an online printing service or e-mail a copy to friends or family. Some printers don't require a PC middleman: They can print directly from a camera or memory card.




Once you've stored and backed up your photos you can erase the memory card and use it again.




How are digital cameras different from each other?




You'll find digital cameras with price tags ranging from $90 to $5,000, although most are in the $200 to $600 range. The main differences involve the resolution of the images they record, the type and quality of the lenses, the mechanics they use for taking pictures, and the options they provide for controlling exposure.




What's resolution?




Resolution is the first item you'll see in a camera ad or spec sheet. It refers to the number of dots, or pixels, that the camera uses to record an image. The more dots, the greater the potential detail. Resolution is expressed in megapixels, or millions of dots. Today's cameras start at 6 megapixels and head upward to 12 megapixels or higher.




More pixels are better, but only up to a point. Even a 5-megapixel camera with a decent lens will produce great 4x6 snapshots and beautiful 8x10 enlargements from a full frame. But if you want larger prints &

or quality prints from cropped images &

a 7 to 8 megapixel camera is a better buy. You'll find plenty of these from top manufacturers in the $200 range.