Digital Cameras: Focus on the Big Pixels

New 5- and 4-megapixel cameras bring sharper pictures and better values.

Alan Stafford

New 5-megapixel digital cameras are shooting bigger and more colorful pictures than ever. They're costly, but fear not: The release of these models is already reducing prices on still-excellent cameras with lower pixel counts.

With one of these shooters, your photos can be detailed enough to display at even 8-by-10-inch print size. The latest cameras are a significant jump from the 2- and 3-million-pixel models that, save for one expensive 4-megapixel camera, previously ruled the consumer market's top tier.

We looked at the first 5.24-megapixel consumer camera, Minolta's Dimâge 7 ($1499). Several 5+-megapixel cameras should follow from other major vendors. Or consider the newest 4-megapixel cameras, which offer compelling value for people who need high-resolution images but are unwilling to pay the premium for a 5-megapixel model.

We tried out a shipping Dimâge 7 unit. As expected, its higher resolution yielded sharper pictures than those from 2- and 3-megapixel cameras, especially with cropped and enlarged images. We saw mixed color results, however.

Sharp Shooter

The Dimâge 7's strength is its sharpness, which lets you zoom in much farther and still retain details (see the print comparison image). An extra-long 7X optical zoom makes the super resolution even more flexible--you can get close with the zoom, then crop and enlarge with software to get even closer. A helpful viewfinder cue indicates which part of the image was used to set focus. But unlike competing cameras, such as the Olympus E-10 (a $1799, 4-megapixel unit), the Dimâge 7 shows you your prospective shot only through its two LCDs (a standard one and the viewfinder). Consequently, you never see a nondigitized view of your picture.

We got mixed results with color and contrast. Test shots taken beneath clouds looked brighter than ones from some other cameras. But bright sunlight shots had muddy colors and hid shadowed details.

Going Hi-Res

Remember that the commonly accepted standard for high-quality printing is 300 dots per inch; the Dimâge 7's best setting creates an image good for just 240 dpi when printed at 8 by 10 inches (see the chart). You'd need images with at least 2400 by 3000 resolution, from a 7+-megapixel camera, to achieve a true 300-dpi print at 8 by 10 inches. An image from a 6-megapixel camera could yield a 278-dpi print, however, which most users would be unable to distinguish from a 300-dpi print, says Chuck Westfall, assistant director for Canon's technical information department.

If you can't see (or won't pay for) the difference a 5-megapixel camera makes, a 4-megapixel unit might be your best bet. Several vendors offer new models in this class.

Canon has just released its $899 PowerShot G2, a 4.13-megapixel model with notable new features. The G2's new three-point focusing system lets you choose which portion of the frame the camera will focus on. The camera's metering system can also adjust the light level for every pixel shot rather than adjusting based on data from a few regions of the frame, according to Canon.

Also new: Olympus's 4.13-megapixel Camedia C-4040 ($999); it has the same case and many of the same features as the C-3040 (an older 3.3-megapixel model), including a 3X optical zoom and a wide f/1.8 lens aperture.

Sony's new 4.1-megapixel DSC-S85 uses a high-quality Carl Zeiss 3X optical zoom lens, and it costs less: $800. Toshiba's 4.2-megapixel PDR-M81 matches the Sony's price; it has a 2.8X optical zoom. Casio's QV-4000 offers 4.13 megapixels and a 3X optical zoom, for under $1000.

Many 3-megapixel cameras still cost as much as or more than higher-end models, but prices are dropping. For example, Kodak's new $449, 3.1-megapixel DX 3900 breaks the $500 price point; it has a 2X optical zoom. If you can do without a CompactFlash slot and an optical zoom, save $50 with Kodak's 3.1-megapixel DX 3700 model.

The Helpful Bit

With affordable 4- and 3-megapixel cameras available--more than sufficient for most uses--vendors are looking beyond resolution to distinguish their products. Like scanner vendors, some camera manufacturers now trumpet color bit depth. The higher a model's bit depth, the greater the range of color captured by the camera and the richer the subsequent image.

Sony's DSC-S85 uses a 14-bit analog-to-digital (A/D) converter, for a total of 42 bits spread over the three color channels. The Dimâge 7 uses a 12-bit A/D converter (for a 36-bit total). Other vendors still have 10- or 8-bit A/D converters. Users with high-end printers will see the most benefit from higher bit depths: Their pictures should show more subtleties in highlights and shadows, as well as more realistic flesh tones.

A greater number of users may notice other tweaks from specific vendors, however, such as Casio's Best Shot feature, included on its QV-4000 and on the older QV-3500EX. With it, you don't have to remember optimal exposure settings for best image quality every time you take a shot: Just pick the best match from the camera's built-in image database--say, a backlit shot of a person's face--and the camera does the rest.

The Minolta Dimâge 7's Flex Focus Point takes another tack, allowing you to pick the focus of your shot, rather than relying solely on the center-weighted focusing typically found in many cameras. Nikon and Casio offer similar features in their respective high-end cameras.

In order to add value, Kodak says it's working on making cameras easier to use--hence the optional docking system the company offers on many of its models. With the dock, you can recharge the camera's battery and download images to your computer more conveniently than with the mass of cables and plugs that you'd otherwise deal with.

More Resolution

To go beyond 5-megapixel resolution, camera technology will need a boost. Forthcoming high-resolution cameras handling bigger, more complex files will require more-powerful digital signal processors, better batteries, larger memory buffers, and more storage, say industry experts. Camera bodies may also have to grow to accommodate the larger CCDs (charge-coupled devices) that are needed for the extra pixels.

Jon Sienkiewicz, Minolta's vice president of digital imaging products, says resolutions will continue to climb, though more slowly--because fewer people will need them, not because of technical limitations. "3.3 [megapixels] is fine for most people," he says. And the lower prices of 3-megapixel cameras will increase their appeal to mainstream buyers, according to IDC Research.

But enthusiasts will likely keep clamoring for more, especially since the promised advent of 6- and 7-megapixel cameras in the next few years may finally put digital models on a par with their traditional film cousins, even at large print sizes. For now, you can still get sharp, high-resolution pictures with a 5-megapixel camera, and nearly as high-quality shots with new, less pricey 4-megapixel models.

Buying Information

Minolta: Dimage 7 Captures highest-resolution images yet, but our color and contrast results were mixed. List: $1499

Translating Pixels Into Print (chart)

Below we list common digital camera and image resolutions, and show what their top images translate into when printed. Even today's high-end cameras can't produce images for large prints at 300 dpi to approximate the sharpness of a standard film photo. But even low-end cameras can yield prints that look reasonably good at 4 by 6 inches.
Resolution	Megapixels 1+	Megapixels 2+	Megapixels 3+	Megapixels 4+	Megapixels 5+
Typical highest image resolution (pixels)	960 by 1280	1200 by 1600	1536 by 2048	1704 by 2272	1920 by 2560
Equivalent resolution for a 4-by-6-inch print (dpi)	240	300	384	426	480
Equivalent resolution for an 8-by-10-inch print (dpi)	120	150	192	213	240
Equivalent resolution for a 2-inch cropped piece of larger image, enlarged to 8 by 10 inches (dpi)	30	37.5	48	53	60