With the high-end camera market currently dominated by SLR (single lens reflex) digicams, you'd think there'd be no demand for a new all-in-one model. But Sony's Cybershot DSC-R1 isn't like any all-in-one ever released. It's got a 10.8Mp (megapixels) sensor, an excellent 5x zoom lens and, crucially, is the first all-in-one to sport the same kind of sensor as a digital SLR. It's a unique package, but how does it shape up?

The R1's entire design, operation and performance is built around its unique sensor, which combines the low noise of a digital SLR with the live screen of a consumer camera. With the screen used for composition, the R1 doesn't need the prism and flipping mirror of a traditional SLR. This not only enables the R1 to operate silently, but also allows Sony to place the lens elements much closer to the sensor.

The lens itself, designed by Carl Zeiss, offers a wide 5x range equivalent to 24-120mm, with a bright optical ratio of f2.8~4.8. The zoom is operated by a mechanical ring, but manual focus is electrically assisted; a lens hood is supplied. The R1's 10.8Mp sensor delivers images with 3888 x 2592 pixels and sufficient detail to make prints at least 2in larger than those provided by budget digital SLRs. Images can be recorded at two JPEG levels, or in RAW mode accompanied by a JPEG.

Best-quality JPEGs measure around 4.5MB each and can be recorded onto CompactFlash or Memory Stick cards; you'll need to supply your own. In terms of design, the R1 is unmistakably a Sony camera, although the swivelling body of its high-end predecessors has been replaced by a more flexible flip-out 2in screen. Rather than mount the screen on the back, however, Sony has fitted it on top of the R1. This can be flipped out or folded back down face-up for waist-level shooting. Alternatively, you can use the electronic viewfinder.

Unusually, the main dial is mounted on the back. It switches between Auto, Program, Manual, Shutter and Aperture Priority modes, along with four scene presets. Exposures run from 1/2,000 to 30 seconds, with a bulb of up to three minutes, while a wide range of sensitivities are available, from 100 to 3,200 ISO. Burst mode fires off three frames in a second, but then pauses as the buffer is emptied.

In use the R1 feels responsive and the flip-out display encourages unusual angles. The images easily out-resolve 6Mp digital SLRs, although,Canon's 8 megapixel 350D comes close. Noise levels aren't quite as low as most digital SLRs, but are far lower than any all-in-one, especially at higher sensitivities. On the downside, manual focusing isn't as easy as with an SLR and the three-frame buffer is small.

Ultimately, though, the choice between the R1 and a traditional SLR depends on whether you need to switch lenses. Remember: many SLR owners never remove their basic 3x zooms. They'd prefer the R1, with its longer 5x range and brighter optics, not to mention higher resolution and flexible composition. So if you're satisfied by the R1's lens range, and sustained burst shooting and precision manual focusing aren't high priorities, then go for it. You'll enjoy higher resolution, more flexible composition and a better standard of lens than you'd get with a budget digital SLR.

The Cmos sensor on the R1 is the same size as those used by budget digital SLRs, boasting more than five times the area of those in existing high-end all-in-ones. Like digital SLRs, the R1 is thus able to deliver much lower noise levels, even at higher sensitivities.

Unlike digital SLRs, the R1 has a large Cmos sensor that can deliver live video to the screen, allowing it to be used for composition like a consumer camera. Sony has exploited this facility by offering a host of optional onscreen features that are impossible with traditional digital SLRs, including grid lines, live histograms and live zebra patterns to indicate areas of overexposure. There's no movie mode, though.

Sony's DSC-R1 is the first all-in-one to combine the low noise and high sensitivity of a digital SLR with the flexible screen of a consumer camera. It also sports a 10.8Mp sensor and a superb 5x zoom.