Casio has finally succeeded at producing an ultra-slim digital camera without sacrificing too much on image quality. Casio's S-series have always been among the slimmest digital cameras, starting with the S100 which featured a lens made of transparent ceramic. The Casio Exilim EX-S770 remains extremely slim at 0.7" thick but produces images of noticeably higher quality than its predecessors. Speaking of image quality, the S770 shows excellent exposure and color, good image sharpness, accurate focus and low purple fringing. The downsides are above average image noise at all ISO levels, although ISO 50 and 100 are quite clean, and noticeable distortion near the wide-end of the zoom range. The Casio S770 also performs extremely well in terms of speed with low shutter-lag, very fast auto focus and even a 3-frame-in-one-second burst mode with flash.

In terms of handling, the S770's size works against it. It is a tiny camera and Casio didn't skimp on external controls. That is normally a good thing but it leaves little room to hold the camera firmly and makes several buttons prone to accidental activation. Since ultra-compact digital cameras which perform better are closer to 1" in thickness, this is an important compromise to consider. The LCD on the Casio Exilim EX-S770 is very nice with good outdoor visibility and customizable brightness, including automatic-brightness based on ambient light. Strangely, the LCD can be set to various color modes. Why anyone would set this to anything else than 'Real' is a mystery. One minor annoyance for travelers is that the Casio S770 requires the use of its docking station to charge its battery.

As for the competition, the S770 is trumped in terms of image quality and handling by several thicker ultra-compact digital cameras. Those include the Fuji Finepix F31fd, the Fuji Finepix F30 and the Fuji Finepix F20. There is also the Canon Powershot SD800 IS which features a wide-angle lens, built-in stabilization and an optical viewfinder for added flexibility. The bottom line is that if a 1" thick camera is too large for you, then the Casio Exilim EX-S770 is a great option. Otherwise, all the ones we mentioned are better and, with the exception of the SD 800, cheaper.