As the current top-of-the-line model in its Cyber Shot W series, Sony's Cyber Shot DSC-W100 shares almost everything with its siblings, the DSC-W70, the DSC-W50, and the DSC-W30: it uses the same ultracompact 6.7-ounce body , 38mm-to-114mm 3X zoom lens (35mm equivalent), and bright 2.5-inch LCD. The W100 ups the resolution to 8 megapixels, sports a textured finish on its metal front panel, and adds a manual-exposure mode, but ultimately isn't a much more compelling buy than the similar-performing W50, which costs between $50 and $100 less.
Like the other models, I found the DSC-W100 to be an easy camera to learn and use, though the frequent trips into the menu system to change the metering scheme, the ISO speed, and the burst mode make it cumbersome to change these oft-used settings. The tiny controls complicate matters further.
Sony's inclusion of a manual-exposure mode strikes me as an odd choice as well. Semimanual modes--program shift, shutter-priority, and aperture-priority--tend to be much easier to use and more practical for snapshooters. Furthermore, since the camera provides only two aperture choices for a given focal length, the DSC-W100's manual exposure is actually quite difficult to use.
One advantage the Sony Cyber Shot DSC-W100 has over the DSC-W70 is a sensor that's capable of shooting at ISO 80. Photos shot at this sensitivity level--and to a certain extent, at ISO 100--are relatively sharp with little noise and few processing artifacts. Beyond that, the aggressive noise-suppression algorithms kick in, blurring and smearing details. Photos print reasonably well to as large as 8x10, but they look a little soft and foggy. In addition to some distortion in the bottom corners at its wide angle, the lens also produces some cyan and magenta fringing on the sides, as well as purple fringing on high-contrast edges.