Digital Focus: Scanning Old Photos
Most of us have a large collection of aging photos that are years, perhaps decades old. Recently, my parents started archiving old photos that date back to the early 20th century, for instance; and I've been squirreling away pictures of me and my sister from when we were kids.
One thing has become clear: No matter how carefully packed or protected, these photos are decaying. There scratches and tears, and the colors are fading--and no preservation efforts in the universe can prevent this.
The only way to make sure that historic photos survive is to scan and digitally restore them.
Plan Before You Scan
Obviously, the first step toward restoring your old photos digitally is to scan them into digital files. But if you want to get a good digital copy of an old photo, it pays to plan ahead. There are a few things you can do to improve the quality of your scanned photos before you ever turn on the scanner.
Consider your source material, for instance. You can scan whatever you happen to have: prints, negatives, or slides. But if you have both prints and negatives stored in the attic, I'd pass on the prints and use the negatives instead (assuming they are in as good or better shape). The same goes for slides: They're preferable to prints, unless they're damaged. Negatives and slides are best because the inks used to print photos tend to fade quickly and unevenly, adding an undesirable color cast to the photos. That's why old photos often have a reddish or yellowish hue.
If you're working with prints, it's worth pointing out that you shouldn't try to clean or improve them. It's easy to ruin old photos by over-handling. If your prints are dusty, use a dry cloth to gently wipe away the grime--and that's all. If something is stuck on, leave it there. Most importantly, never use any kind of liquid to try to clean a photo. If your photo is torn, don't try to fix it with tape--especially on the print side. Most adhesive tapes discolor over time, and you'll likely end up with a yellowish stripe running across your photo.
We're almost ready to scan. Before you start, clean the platen--that's the glass scanning bed of your scanner. To do that, apply a small amount of cleaning liquid to a cloth and wipe the glass. Don't apply liquid directly to the platen, because it could leak into the mechanism. Make sure the glass is completely dry before you lay a photo on it.
Scan Your Old Photos
Now we're ready to scan. But what settings should you use? It really depends on the way you intend to use your digital files. If you were planning to upload a digital copy to your Web site, for example, you might use the scanner's lowest resolution. However, I'm going to assume that generally when you're scanning old photos, your goal will be to restore and archive them for future generations. So let's scan them so that high-quality prints can be made from the files.
Most scanner software lets you specify the target print size and resolution in dots per inch. A good rule of thumb is to set up your scanner software so it'll create 300-dpi prints at whatever maximum print size you expect to make--usually about 8 by 10 inches. A typical scanner control panel set to make 300-dpi, 8-by-10-inch prints would look something like this:
If your scanner software makes you specify the scanning resolution of the initial image rather than the final print size, then you'll need to do some math. To get the scanning resolution, divide the target print size by the size of the original, then multiply that by 300. You'll need a very high resolution to create usable prints from slides and negatives, since their surface area is so small. For example, if you're scanning a 1.5-inch-wide 35mm slide, you'd need to set the scanner resolution to about 3000 dpi.
After the scan is complete, save your photo as a TIFF or as a JPEG at the highest-quality setting with the lowest file compression. If you add any compression to reduce the file size, you'll be throwing away image quality.
Next week, let's continue the process by using some techniques to improve old, damaged, and faded photos.