Pentax Optio S4

A table of the digital images taken with the pocket digital cameras

Choosing between the Pentax, Casio and Canon is a tricky business as all have their individual strengths and weaknesses. One of the Optio S4's advantages is the 3x optical zoom lens that's somehow packed into a frame the same size as the Casio, albeit 9mm thicker. Another reason why the S4 will tempt you to spend an extra £46 over the Casio is the 4-megapixel sensor, which produces 2,304 x 1,728 images. Where the Casio is limited to 1,600 x 1,200, the S4 allows you to take a photo and crop it while retaining more detail than the EX-S20's full-sized image. But, at maximum quality, you'll only fit three photos into the 11MB of internal memory, so budget for a high-capacity SD card if you decide to purchase.

Unlike the EX-S20, the Optio doesn't have a dock option, but it's easy enough to transfer images or data files to and from your PC over the USB 1.1 interface. Pentax bundles a charger, but the AC adaptor for in-camera charging isn't supplied.

The S4 provides a decent array of controls including manual white balance, manual ISO selection, sharpness, contrast, saturation and exposure compensation. You can set focus manually, or by one of 49 selectable points; three light-metering modes are also on offer.

Many of the options can be stored in memory so they're remembered next time you turn on the camera, which incidentally takes only 2.1 seconds: impressive for a telescoping lens. Shot-to-shot time isn't so good though - it's almost three seconds at best quality. It's quick to browse through the photos though, and we appreciate the bright 1.6in CCD and the 4x playback zoom. There's also a live histogram. If we've one complaint it's the tiny direction pad, which selects menu options without you intending it to.

Quality is easily on a par with the Casio, with the bonus of a much better resolution. Outdoor shots were generally well exposed, sharp and with well-saturated and accurate colours. Indoors, the S4 displayed great flash performance and good white balance. Macro ability easily outstripped the Casio, capturing an area of just 42 x 32mm. Movies are 320 x 240 and have half the frame rate of the Casio, but are still good quality.

With good build quality, thanks to an all-metal casing, the S4 is a desirable camera. It's highly pocketable and offers great quality. If you need a zoom, it's the camera to choose.