The Sony DSC-P31 is equipped with a 5.0mm F2.8 lens which is 33mm in 35mm equivalent. The Multi Point auto focus range is from 3.9 inches to infinity with manual focus presets for 10cm (3.9"), .5m, 3m, 7m, or Infinity.

The Zoom Control allows up to 3x digital zoom in Record mode if the LCD is on. This diminishes the quality of the image.

In PlayBack mode, the Zoom control allows up to 5x magnification of the recorded image on the LCD when the "T"elephoto side is depressed. Also the "W"ide button allows the user to switch to Index mode in Playback.

The eyelevel optical real-image zoom viewfinder has a field of view of approx. 80% of the captured image. There is no diopter adjustment. The LEDs indicate card activity/Self-Timer, Autofocus/Auto Exposure Lock and Flash status.

The built-in flash has modes for Auto flash, Fill-flash or Flash Cancel and Red-eye Reduction can be enabled via the Setup menu. Accessible through the Scene Mode is a Twilight Portrait mode that allows for a slow shutter plus flash. The working range for the flash is 1.3 to 12.5 ft.

The Mode Dial has positions for SETUP, Movie, Playback, Record and SCeNe. The SCeNe mode has settings for Twilight, Twilight Portrait and Landscape.

The POWER SAVE switch when ON helps extend the life of the AA batteries by lowering the intensity of the LCD backlight.

The MENU button calls up or dismisses the onscreen menus. The DISPLAY / LCD buttons turns the color LCD on/off and also controls the display of overlay information.

The 4-way selector lets you navigate through the menus or select images during playback. Pressing it in the center accepts selections. In record it lets you select the flash mode, spot metering, self-timer and Quick Review mode.

The I/O ports are found behind a door on the back and include a fast USB port for transferring images to the computer and a Video Out port to display images on a TV.

Also on the back is a DC INput jack for connecting an optional AC power supply.

Located on the bottom is the Memory Stick card slot. The DSC-P31 comes with an 8MB Memory Stick and can use any capacity Memory Stick card. The Memory Stick is easily removed by pressing it inward which makes it "pop" out.

Power comes from two AA type batteries. The P51 is supplied with high-capacity 1750mAH NiMH rechargeable batteries and an overnight AC charger. It can NOT be used with an InfoLITHIUM battery pack, it runs strictly on AA type batteries. You can use alkalines in a pinch but expect a much shorter runtime and it is recommended to keep the color LCD turned off.