The unique feature of Sony's CD400 Mavica is a built-in mini-CD recorder, a clever solution that simultaneously provides affordable portable memory and long-term archival storage. The camera also features a 4-megapixel sensor, a 3x optical zoom Carl Zeiss lens, a jumbo 2.5-inch display, and long-life rechargeable lithium-ion battery.

The CD400's 4-megapixel sensor captures a tremendous amount of detail, allowing sharp 11-by-14-inch prints with pixels to spare. If you're currently using a high-quality 35mm point-and-shoot, expect to see as much detail in your digital pictures as you currently see in your film photos. A 3x Carl Zeiss optical zoom lens (34-102mm equivalent) helps you to capture exactly the picture you want, and an additional 2x digital zoom (6x total) further magnifies your image. Remember, however, that digital zoom tends to reduce the sharpness and detail of your image, so it's best used sparingly. In low-light situations (a particular weakness for many digital cameras), a focus-assist lamp sends out a small patterned beam to help the camera accurately determine distance. To save space, there's no traditional optical viewfinder to look through. Instead, to compose your images or review shots you've already taken, the CD400 uses a 2.5-inch color display. The advantage to using the LCD to frame your shots is that the screen lets you see exactly the picture you'll capture. The disadvantage is that you can't turn off the screen and just use the optical viewfinder to extend battery life. Fortunately, the included rechargeable battery holds a relatively good charge.

The engineers at Sony have gone out of their way to make it as easy as possible to share your images online. For example, the e-mail mode stores a lower-resolution version of your picture on the disc in a separate folder from the full-size version. This compact file lacks the detail of the original, but has a small file size, making it ideal for e-mail attachments. In addition, a video e-mail mode captures highly compressed, less-detailed movie clips that are also small enough to easily e-mail. With the time, expertise, and the right software, owners of any digital camera can create these more compact files on their home computers, but Sony saves you this trouble. More advanced photographers will appreciate manual focus, a 14-bit A/D processor that captures more gradations in color than most digital cameras, and an uncompressed TIFF mode for recording the highest-quality photos.

The CD400 uses Sony's excellent InfoLithium battery system, which not only holds a respectable charge, but also displays on screen how many minutes of power remain. Both the battery and the charger are included. Because the battery is unique to specific Sony models and can be nearly impossible to find when on the road, we strongly recommend getting a spare if you're planning to take the camera on extended outings.

In movie mode, the camera captures video clips with sound at resolutions up to 320 x 240 pixels. Unlike most digital cameras, the length of each video is limited only by the amount of memory left on the CD. The limited resolution of these clips guarantees that this feature won't replace your camcorder, but it's perfect for when you just want to capture a quick movie and e-mail it to a friend or relative.

With a traditional digital camera, images are stored on memory cards, then transferred to your computer via a cable or card reader, and ultimately archived by recording on a CD-R or other high-capacity medium. Sony's CD Mavicas simplify this process by recording images directly to CD, using a 3-inch miniature CD recorder integrated into the back of the camera (hence the camera's rounded shape). These discs are substantially smaller than traditional 5-inch CDs, and only hold about one-fourth as much information (156 MB instead of 650 MB), but this is still enough space to store over 60 photos at the camera's highest-quality compressed mode. Each disc costs a couple of dollars. To transfer pictures to your computer, simply remove the disc from the camera and insert it into your computer's CD-ROM drive. Unlike images recorded on memory cards, pictures taken on a CD-R are permanently burned into the disc, instantly providing a digital "negative" for archiving your photos. If you prefer to transfer your images in the traditional way, just use an erasable/re-recordable CD-RW disc and connect the camera to your computer with the included USB cable. After transferring the images, you can erase the CD-RW disc to ready it for another batch of photos.

At 5.5 by 3.75 by 4 inches, and 23 ounces, you won't slip this one into your shirt pocket, but it's still one of the smallest disc-based cameras available. The CD400 fits nicely into most SLR camera carrying cases.

The package includes the CD400 camera, NP-FM50 battery, AC-L10 cable for in-camera charging, six 3-inch CD-R discs, one 3-inch re-recordable CD-RW, shoulder strap, AV cable, USB cable, and software on CD. Everything you need to get started is included in the box, but we recommend these accessories to make the most of your camera: a carrying case, additional 3-inch CD-R or CD-RW discs, and a second battery (especially if you're taking the camera on extended trips). Compatible accessories for this camera are listed near the top of this page.