Digital cameras come in two basic flavors. Most people are familiar with the convenient point-and-shoot--the electronic descendant of the cheap, compact and once ubiquitous Kodak Brownie. These cameras let shutterbugs preview shots on a tiny screen and cost a couple of hundred dollars each. Less common are digital single-lens reflex (D-SLR) units--the computerized versions of the classic through-the-lens, 35-millimeter-film cameras, which offer far higher image resolution, along with much loftier prices. (They can exceed several thousand dollars.)

Now comes Sony's Cybershot DSC R1 digital still camera, the first of a new category of reasonably affordable ($999), all-in-one electronic picture-takers that combines some of the best features of existing high- and low-end digital designs. I have been interested in purchasing a D-SLR for some time but have been waiting for prices to fall before dropping a bundle on one. Could the R1 be a useful alternative? I tried it to find out.

The first thing you notice about the R1 is its considerable bulk and heft. At around two pounds, it is clearly a two-hander. But the zoom lens, which extends all the way from an effective 24mm (wide angle) to 120mm (short telephoto), makes left-hand adjustments pretty much standard procedure anyway--especially if you often shoot entire rooms, big-group photographs or expansive landscapes. So when this slick package of high-tech optical design slips readily into your grip and handles smoothly enough thereafter, you don't complain too much about the weight.

The second thing you notice is the R1's stalk-mounted, live-view screen sitting topside. Like a point-and-shoot's monitor, the R1's two-inch-wide, high-brightness liquid-crystal display (LCD) presents the photograph before you snap it. But it also raises up, tilts and swivels to accommodate the photographer's vantage point, whichever way the lens points. Once I realized the implications of this unique feature, the next step was obvious: a series of arm's-length self-portraits.

The procedure goes something like this: (a) Face the screen fully front so il maestro can compose the frame. (b) Trust the automatic settings and adjust the mug in the forward-rotated, live display, stare at the lens, depress the shutter button to focus and then punch it. A barely audible "click" sound follows immediately. (c) Repeat steps a and b as necessary. (d) Enter a less well-lit room, assume the arms-extended position and mash the button; a red laser probe abruptly ranges across your cheekbone, a pop-up flashlamp blinks open, and blinding strobes flare. Minor shutter lag ... then muted click. (e) Repeat step d as desired.

As your vision slowly recovers, you can see that the unique all-angle, real-time display could finally enable photographers to appear properly positioned and posed in timed shots of small groups, for example. And for less common camera perspectives, such as the low-angle, pet-level scan I later took of my neighbor's new puppy, the flexible monitor can be invaluable. In the latter case, the R1 became a view camera.

But what is truly surprising about the R1 is the outstanding quality of those initial impromptu head shots (all vanity aside, of course). When scrolled across the LCD screen (and later printed out on paper), the images are all fine detail and nicely rendered color and contrast. Sans insidious red eye, as well. Automatic imaging mode notwithstanding, the results are considerably better than those from any pocket digicam. In fact, the photographs look to be nearly on a par with those produced by professional-grade D-SLRs.

At this point, the reason for the R1's almost inaudible click finally hits home. The new camera is not an SLR; it lacks a shutter altogether. The SLR's clicking shutter mechanism--the moving mirror and prism device that momentarily redirects the light passing through the lens from the viewfinder and into your eye to the 35mm film (in nondigital models) or the large-scale silicon imaging array sensor (in their digital counterparts)--seems absent. A glance into the R1's viewfinder confirms this suspicion; rather than showing a bright optical field, the camera has a miniature electronic screen that displays what the lens sees. [break]

"Much of the R1's novel design derives from our choice of sensor," says Mark Weir, Sony's product manager for digital cameras. "As far as we know, never before has a camera been built around a large-scale sensor--one with big pixels that can grab a lot more light than the smaller pixels used in point-and-shoot sensors--that can generate a continuously, and rapidly updated, image for the live-preview display." Large-scale sensors, which are sometimes called advanced photo systems (APS) or APS-class systems, are many times the size of the devices used in point-and-shoots.

Weir explains that existing D-SLRs need traditional shutter mechanisms because their multimegapixel image sensors can produce an "exposure" for only a brief period (when the shutter engages). These imagers must operate intermittently because they run very hot and hungry for battery power. During the rest of the time, the D-SLR user sees an actual, optical scene in the viewfinder--one that only generally relates to the forthcoming photographic image, which is determined by the camera settings. In this case, what you see is not necessarily what you get.

Developing a suitable, always-on APS sensor was the key to the new design approach, Weir continues. Sony engineers chose to base the R1's big, 10.3-megapixel (21.5mm-by-14.4mm) sensor on improved complementary metal oxide semiconductor (CMOS) technology rather than on the charge-coupled device (CCD) sensors often used in D-SLRs. Beyond the broad dynamic range, low signal-to-noise ratio and extraordinary light sensitivity that all APS sensors provide, the advanced CMOS array in the new camera affords several exclusive benefits: significantly reduced power consumption to ensure reasonable battery life and, especially, lower operating temperatures. "Heat is the enemy of electronic imaging," Weir declares.

Once the new image sensor was perfected, Sony engineers matched it with a high-performance Carl Zeiss zoom lens, which takes up the space vacated by the shutter mechanism. This relatively fast (with a maximum aperture of F2.8 to F4.8) 35mm-equivalent lens complements the big sensor well. For instance, the lens is designed to ably distinguish fine gradations of tonal contrast.

As with a point-and-shoot digicam, the lens is a fixed or dedicated optical system; the R1 does not support easily interchangeable lenses. The broad zoom capability compensates for that disadvantage somewhat, as do the strap-on long-telephoto and macro (close-up) lenses one can buy as accessories. The upside of the nonremovable lens, Weir says, is that the sensor system can be specially tailored to the optical characteristics of the Zeiss zoom, which greatly improves the photographic results.

There are a few other drawbacks. Close-in shots are limited to a range of about a foot, and a video-capture mode is not included. The high-speed burst-shooting mode, which is useful for unpredictable, fast-moving subjects such as uncooperative kids or pets, is limited to a paltry three shots maximum.

But add in a very capable digital image-processing system, and the R1 offers pretty much all the amateur photo enthusiast could want, at a price that won't break the bank. And although the hybrid approach leads to some compromises, the new R1 seems a distinctive take on the digital camera--one that should spawn followers. For now, however, the Cybershot DSC R1 is in a class of its own.