Though no great beauty, the 635 looks clean and simple: its plastic, two-tone body is gray and silver. The camera is more pocketable in a coat than a shirt, and it weighs a moderate 8.3 ounces with batteries and media. The 635 feels solid for a model of this price, and its controls are logically placed. The menus, too, are sensibly designed and unusually well labeled, although they aren't terribly speedy to operate.
For an entry-level snapshooter, the 635 offers a better than average feature list. The 2.8X zoom lens covers a focal-length range of 40mm to 110mm (the 35mm-camera equivalents). Exposure options include programmed-auto mode, four scene modes, and exposure compensation to plus or minus 2EV. The 635 captures stills as JPEG files, for which two resolutions and two compression levels are available. It also records 320x240-pixel MPEG-1 video with sound in clips as long as your card capacity permits. Some worthwhile extras are light-sensitivity settings from ISO 100 to ISO 400; adjustable color saturation and sharpening; and HP's Instant Share system, which simplifies image printing and sharing.
The 635's performance is a bit less impressive. At best, autofocus speed is fair in good light and relatively slow in dim conditions. The approximately 4.5-second start-up isn't terrible, but we were annoyed by the 1.3-second (including AF time) shutter lag and the 4- to 6-second delay between shots. The 1.6-inch LCD is slightly disappointing; it isn't very sharp and suffers from a slow refresh rate. But the tiny optical viewfinder is acceptably crisp. Battery life is very good. On a full charge, we were able to fire off 680 photos, with the flash firing on a little more than half of them. The flash range is 8.2 feet.
We doubt that the 635's pictures will win any awards, but they're fairly good compared with those of similarly priced competitors. Colors are reasonably accurate and vivid, noise is low, and sharpness and detail are about average. However, in our test shots, bad exposure, blown-out highlights, and skin tones that were a little too warm appeared a bit more frequently than we would have liked.