The Optio S10 may have the same sensor as the Optio A30, but it is at heart a very simple point-and-click snapshot camera. It has simple controls and only a basic set of features, although these days ‘basic' can include quite a lot. It has three main operating modes, as selected by the Mode button on the D-pad. These are program auto, a fairly short selection of scene modes (including a portrait mode with face detection) or Pentax's Auto Picture mode, a sort of super-auto in which the camera automatically selects which scene mode is most appropriate for the type of photo being taken, which it does with remarkable accuracy.
Despite its simple ethos the S10 does manage to pack in a decent list of menu options, including spot or wide-area focusing, spot, C/W or multi-zone metering, as well as adjustable contrast, saturation and sharpness. Most of the camera's option are found via the buttons on the D-pad, with multiple focusing options including pan focus, infinity focus, super-macro and manual focus, as well as a 10/2-second self timer, continuous shooting and a setting to use the optional infrared remote control. Naturally at this price the S10 lacks the mechanical image stabilisation of the A30, instead relying on increased ISO sensitivity to reduce shutter times in low light, so-called "digital image stabilisation".
Like most Pentax cameras the S10 has the useful ‘Green Mode' button, which is a polite name for an Idiot Mode. If you get out of your depth with the camera's functions, pressing the green button will reset the camera to full-auto mode, however if you get out of your depth with a camera as simple as the S10, then you should probably not be allowed to go to the bathroom without adult supervision.
Other features include a VGA 30fps video mode with mono audio, although the zoom lens cannot be used when shooting. There are several features in playback mode as well, including resizing and cropping, digital filter effects, automatic red-eye removal
and of course the frame composite mode.