O say that Margo Hochuli-Wallman is a photography enthusiast would be an understatement. Ms. Hochuli-Wallman, a 49-year-old math tutor in Pittsford, N.Y., has been taking pictures since she was 10, chronicling her life and that of her family through the years.
Her snapshots, now numbering in the thousands, are painstakingly cataloged and preserved in several dozen albums. "I'm a little sick that way," she confessed.
When Ms. Hochuli-Wallman switched to a digital camera a year ago, she began to scale new photographic heights. Now she routinely sends pictures via e-mail to friends and family. At family gatherings, she wields her camera with the agility of a combat photographer, and her relatives then gather around her computer for an instant slide show before they leave.
But Ms. Hochuli-Wallman and millions of other digital shutterbugs are facing a problem. How do they ensure that their treasured digital photos will remain intact for generations to come?
If stored properly, conventional color photographs printed from negatives can last as long as 75 years without fading. But photographs archived on a computer hard drive are not so easily preserved. Not only have computers been known to crash, permanently wiping out their contents, but there are limits on the longevity of Zip disks and other large-capacity storage disks used for backups. Further, as hardware becomes obsolete, transferring files to a next-generation machine can be tricky.
"The digital shoe box is very fragile," said Peter Hite, president of Media Management Services in Houston, a consulting firm that helps companies manage their digital and historical archives.
Mr. Hite is a former photography teacher who has yet to abandon his conventional camera in favor of a digital one because of the work involved in long-term archiving, he said. He began to think about the problem recently, he said, when he noticed how many of his friends had started using digital cameras.
"They just assume it's going to be around for a long time," he said. "They think, ĀAs long as it's ones and zeros, I'll be O.K.' "
Mr. Hite recommends that people follow a simple set of guidelines. "First, back up, back up, back up," he said.
There are drawbacks, of course, to putting files onto a storage medium that is likely to become obsolete. Mr. Hite pointed to the example of eight-track music tapes, which were popular in the 1970's but are seldom played now because the equipment is considered obsolete. "Zip disks are essentially the eight-tracks of today," Mr. Hite said.
Even if the backup medium does not become obsolete, its durability is not guaranteed. Mr. Hite said the life span of a CD recorded with a CD burner could be as short as five years because of exposure to humidity and extreme temperatures. And magnetic storage media, like floppy disks, can begin to deteriorate after as little as 18 months because of abrasion and demagnetization.
Mr. Hite said he used a Web-based backup service for all his files, but that can also have its drawbacks. The first service Mr. Hite used went out of business, so he had to switch his files to another Web company.
Another guideline is the safety-in-numbers principle. Distribute your digital photos widely, Mr. Hite said, or even designate a family historian to get a copy of every family photo taken. Mr. Hite also recommends that people make prints of their digital photos.
Ms. Hochuli-Wallman follows two of Mr. Hite's three suggestions. She prints out about half the photos she takes, and she sends multiple copies to friends and family. But she does not have a backup method for the 500 or so digital photos that reside on her hard drive.
Jay Chenoweth, who runs a welding supply business in Houston, is every bit as prolific a photographer as Ms. Hochuli-Wallman. He sends many of the photos he takes to others, but he seldom prints his photos, and he also does not make backups in any systematic way.
Mr. Chenoweth prefers the paperless route because his guest room is already crammed with thousands of family photos taken over the years. "I'm just happy I don't have to keep buying boxes and jamming them into that extra bedroom," he said.
Mr. Chenoweth said he planned to transfer his digital pictures to newer media as the years passed. In digital archiving parlance, that practice is known as migration when digital information is transferred from old technology to new technology.
The process of migration grows more complicated when the information that is transferred cannot be retrieved or used without specific software. Consider the widespread frustration, for instance, if the popular TIFF format (files with the extension .tif) for saving digital photos were to be replaced by another, and all TIFF files had to be converted to the new format.
Even prints are not necessarily the best solution. Stored properly kept at room temperature and shielded from light in an acid-free box or photo album conventional photos last much longer than those produced by inkjet printers.
Epson and other printer manufacturers have started selling printers that use longer-lasting ink and paper. Depending on the paper you use and how well you protect your prints, photos printed on Epson's 2000P desktop printer, which costs $899, can last as long as 200 years, the company says. The printer uses inks with special pigments, which cost more than dye-based ink, and long-lasting paper.
"Ink and paper systems could be engineered to be as good as or better than conventional photographic paper," said Howard Taub, director of the Printing and Imaging Technologies Center at the Hewlett-Packard Laboratories in Palo Alto, Calif. Hewlett-Packard also makes archival printers, inks and papers.
But even 200 years might not be long enough for Ms. Hochuli-Wallman, who wants to preserve her photos for many future generations of offspring. "How long do I want them to last?" she asked. "Forever."