Q: We're creating a gallery of original paintings and prints and putting thumbnail versions of the art on our Web site. We've been scanning photos of the art using a flatbed scanner, which is cumbersome. Will the $300 to $500 digital cameras on the market capture the art work with enough resolution for print and Web production? Some pieces are two feet-by-three feet or larger in size.

A: An inexpensive digital camera may capture enough pixels for print or Web work, depending on the size of print, but the color quality may miss the mark. True, lots of top-quality commercial photography is shot with digital cameras, but these are professional cameras priced upwards of $2,500. Compared to these Madison Avenue-grade jobs, the $200 to $500 mom 'n' pop models take major shortcuts in capturing color, and these are likely to affect the quality of the image you're trying to capture.

Color Me Cheap

First, here are some basics about digital cameras. Digital imaging works in a sort of paint-by-number fashion. Each picture gets broken into tight rows of tiny dots; each dot is a pixel. Digital cameras rely on sensors called charged couple devices (CCDs), which assign a color number to each pixel. That number gets recorded as a combination of red, green, and blue.

High-priced digital cameras have three CCD sensors--one each for red, blue, and green--so the camera can capture the full color value for every pixel. That ability doesn't come cheap, though, since there are three times as many CCDs and three times as many tiny motors whirling them around to capture all that color information quickly.

Digital cameras in the $300 to $500 range have only one CCD sensor. Each pixel-sized microsensor is layered with a red, green, or blue filter. That means each pixel is committed to measuring only red, green, or blue, not the full combination of all three.

As a result, each pixel is missing two-thirds of the RGB color information. A pixel with a red value is missing the blue and green values, for example. To fill the color gap, each pixel borrows missing color values from neighboring pixels.

This process of interpolation (called striping) relies on some high-powered math to estimate what the actual RGB value of each pixel really is, and generally it does a good job, especially where color changes are gradual.

But with highly textured subjects where color changes are frequent and unpredictable--such as patterned textiles or detailed paintbrush work--the color interpolation that takes place during striping starts making mistakes. A gray texture may show bands or spots of color. Or a rich, color-blending brush stroke might appear mottled and indistinct. That's interpolation hitting the wall.

Of course, the cheap digital camera may give you adequate quality for Web presentation, depending on the artwork and your own perceptions. But keep an eye out for the potential image defects mentioned above. Otherwise, I'd suggest you shoot your artwork with a conventional 35mm camera and have the film digitized in one of ways noted below.

Photo CD. Drop off your negatives at a photo processing shop that offers Photo CD service. It'll develop the negatives and scan them onto a CD-ROM, usually for around $1 per picture. The color quality of 35mm film is far better than that of cheap digital cameras and far better than what you'd get scanning pictures with a flatbed scanner. The Photo CD file for each picture includes five image resolutions, from a 128 pixel-by-192 pixel thumbnail to a 2,048 pixel-by-3,072 pixel, print-quality image.

Kodak PhotoNet. If low resolutions for on-screen display are good enough, check out Kodak's PhotoNet online service (www.kodak.photonet.com). PhotoNet processes the film, digitizes it, and posts the images on a Web site in JPEG format. (AOL will offer a similar service to its customers, called You've Got Pictures, in partnership with Kodak.)

To use PhotoNet, take your 35mm or Advanced Photo System film to the PhotoNet retailer in your area and check the Kodak PhotoNet box on the film envelope. (With more than 30,000 such retailers in the United States, even my local Albertson's and Safeway stores offer the service.) If the film envelope lacks a PhotoNet box, just write Kodak PhotoNet online in the envelope's Special Instructions area along with your e-mail address.

The PhotoNet service does cost extra, and pricing is set by your photo retailer. In my area, in addition to the standard film and print charges, outlets typically charge about $4 for 1 to 15 shots, $5 for 16 to 27 shots, and $6 for 28 to 36 shots.

When your film's ready, you'll receive an e-mail message asking you to pick it up. In addition to negatives and prints, you'll also get an access code for accessing and downloading the digital versions.

To see your photos, you first have to register with the PhotoNet Web site. After entering basic information, you'll be given a password and a user name. (The password is for getting onto the site, but each film order has a different access code, which increases the security of your pictures.)

Now just go online and log in with your name and password. To view your roll of film, enter the access code, and you'll see an index with an array of thumbnails. Click each thumbnail to view larger thumbnails. Download a thumbnail if you want it, or download the full-sized version from a separate menu.

Kodak PhotoNet will have six different resolutions of your pictures: tiny (50 pixels by 34 pixels), small (64 pixels by 43 pixels), medium (96 pixels by 64 pixels), large (160 pixels by 107 pixels), larger (384 pixels by 256 pixels), and full size (768 pixels by 512 pixels).

Your photos are automatically kept online for 30 days, but you can extend that period by paying $2.99 per month.

Check the Kodak PhotoNet Web site for other options: sharing photos online, ordering reprints, or purchasing novelty items such as T-shirts that bear your photos.

© 1998 Bob Weibel. All rights reserved.

Bob Weibel is a writer in Ashland, Ore., a former senior technical editor for Publish, and the coauthor of Desktop Publishing Secrets and The QuarkXPress Book, Windows Edition (both from Peachpit Press). Send questions to Bob via bweibel@aol.com or care of Computer Currents.

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