Casio has integrated a spherical lens and a high-sensitivity CCD into a single component. The lens has a maximum aperture of F4.2 and a fixed focal length of equivalent to a 35mm lens on a 35mm cameras. It is a non-auto focus (fixed) focus lens with a range of 80 cm / 2.6 ft to infinity.

The optical viewfinder is large and bright, it shows approximately 85% of the captured image. There is no diopter adjustment.

The built-in flash has modes for auto, fill, red-eye reduction and off. The working range is approx. 0.8 to 2.0 m / 2.6 to 6.6 ft.

Located on the top are the power on/off and shutter release buttons.

The back is dominated by a large, 2-inch color LCD monitor. To give you an idea just how big it is, here's the EX-S3 compared to the Pentax Optio S and the Minolta DiMAGE Xt.

The controls are minimal but effective. All camera settings are changed via onscreen menus called up by the MENU button and using the 4-way controller. The operating mode is selected with the PLAY - RECord switch. The DISPlay button turns the color LCD on/off. The 4-way controller is also used to activate the digital zoom (if enabled.)

I was very happy to see that Casio made the 4-way controller much larger and easier to use than the tiny one that was on the EX-S1 and EX-S2.  I guess it does pay for us to complain about those badly designed things.

The EX-S3 has 10 megabytes of internal memory for saving images and movie clips. Optionally, any size Secure Digital or MultiMedia Card can be used via the expansion slot on the bottom. Image data can be copied to/from internal memory and a flash card via the Playback menu.

The camera must be placed in the included cradle to connect with a computer via the built-in USB 1.1 port and transfer data.   It also charges the battery.

The super-slim NP-20 lithium battery pack is charged whenever the camera is docked in the cradle. This 3.7 volt battery is rated at 680mA and Casio claims it will power the camera for 2 hours in playback or 80 minutes (approx. 480 shots) in record mode with the LCD turned ON and not using the flash.

Recharging time is approx. two hours if the battery is fully depleted.