The camera is compact in design, has a metal body and delivers high quality digital SLR photography. The Pentax K100D has many features including 6.1 megapixels CCD with primary colour filter and the PENTAX Shake Reduction system (SR) compensating for shooting in low light conditions.

The Pentax K100D can be powered by 4x AA lithium/alkaline/rechargeable Ni-MH batteries or by 2x CR-V3 lithium batteries with images being stored on SD memory card.

ISO sensitivity is auto or manual with manual ranges of 200/400/800/1600 and 3200 and White Balance modes are auto, manual, daylight, cloudy, shade, tungsten, fluorescent, flash. The Pentax K100D has a built-in retractable P-TTL auto pop-up flash with flash modes of auto, on, off and red-eye reduction. There is also an AF assist lamp which can be used via the built-in flash.

The Pentax K100D exposure modes include; auto picture, picture, scene, programme AE, shutter priority AE, aperture priority AE, metered manual and bulb. Picture mode includes; portrait, landscape, macro and action and Scene modes include night, surf & snow, sunset, candlelight, kids, pet, museum and text.

File formats are JPEG, RAW, DCF, DPOF and PRINT Image Matching III and images can be viewed on the 2.5" TFT colour LCD monitor which has brightness adjustment and a wide angle view. Playback modes include; index, image rotation, slideshow, one shot and histogram with the digital filter offering black & white, sepia, colour, soft, slim and brightness.

the Pentax K100D is PictBridge compatible.