SCANNERS & SCANNING

by Joelle Steele

Scanning technology was around long before the digital age. But with the advent of desktop computing and photo editing software, scanners have become commonplace computer peripherals.

For many people, scanners have provided the opportunity to scan old photos, repair them, and share them with others. It also allows for electronically archiving them without the need for the special handling and storage that antique photos normally require to prevent damage and deterioration.

SCANNERS

There are basically four kinds of scanners:

Drum Scanners. Drum scanners are round, and the item to be scanned is wrapped around the drum and scanned at very high resolution up to 5-6,000 dpi. These scanners are the best, especially for large scale art/photo prints. But, they are also the most expensive ($5,000-$20,000), require some training to use correctly, and are very slow. They create far less image distortion than do flat bed scanners.

Flatbed Scanners. These are the most common scanners used by the majority of people. They are highly affordable ($300-$900), can produce excellent images, but can also create image distortion if the item being scanned is not held firmly against the glass surface while scanning. They are limited in the resolution at which they scan, usually an average of 300dpi to 600dpi, and a few at a maximum of 1200 dpi. That said, for most image projects, they are more than adequate.

Film Scanners. These scan negatives and slides, but they are likewise a little costly. Some flatbed scanners come with transparency adaptors for scanning negatives and slides (which is what I used when I digitized all my negs and slides). The very best film scanners have high resolution (about 7,000 dpi), are easy to use, and are pricey, but affordable at $350-$500).

Portable Document Scanner (PDS). You can use these for an image, but you won't get high resolution and because they are hand-held, you will ;ikely get considerable distortion. They are really designed for printed documents. They are inexpensive ($65-$150).

So, in the long run, if all you're doing is restoring or editing photos that are no bigger than the 8-1/2" x 11", a good flatbed scanner with a minimum 600 dpi, will probably do the job. Avoid the  inexpensive 3-in-1 devices that scan, fax, and copy. In my experience, they don't produce good scans of photographs.

SCANNING

You might be tempted to forego the scanner and just use your digital camera to duplicate your ancestor's damaged photograph. I've done both, but I get much better results from scanning at high resolution (minimum 600 dpi). This is very important when you are restoring a photo, because you need to have a lot of pixels (those little square things you see when you enlarge a photo onscreen) to successfully repair damaged areas and still have the photo look like it did when it was first taken.

Don't disassemble or scan photos under glass, such as Daguerreotypes, ambrotypes, tintypes, or images framed with convex (domed) glass. You'll likely end up damaging these fragile images, and the long exposure to scanning light is harmful to them. Use a camera to photograph these types of items instead. Some oversize items, such as panoramas, may need to be scanned in overlapping segments.

With print photos, very carefully remove the photo from its frame and mat, if it is currently mounted. Do not try to remove old cellophane tape or any smudges of dirt, as doing so can often cause additional damage that is even harder to restore digitally. Place the photo face-down on the scanning bed, making sure it is very straight. Scan it at a minimum of 600 dpi.

SCANNING TIPS

Always scan in color if you're going to restore a photo, even if it is a black and white photo. The only way to tell the difference between a spot of mold and a facial mole for sure is in the coloration of the spot. You can always convert the file to black-and-white when the restoration is done.

To avoid having the edges of a photo auto-cropped by your scanner, select the option to scan the entire bed (the platen). This is especially important if you are scanning something that has very light-colored edges, as those edges might get cropped out.
If you are trying to scan the page of a book, be sure to hold the scanner lid down firmly (but do not press down too hard) so that the page sits as flat as possible on the glass. This will prevent the image from being distorted or having dark shadowy edges.

If your scanner is producing images with lines running down the middle of them, this is usually the result of a cheap scanner, dirt inside the scanner (small bits of dust create lines), or the  calibration with your computer is not happening for some reason. Read the help file for your scanner and clean it and/or calibrate it. If neither is possible, you will have to edit out the lines or purchase a better scanner.

SAVING YOUR SCANS

Save your scanned photograph as a TIF file, not as a JPG or JPEG file. A JPG is a compressed file for use in transmitting photos over the Internet. It's structure is unstable for long term use as it slowly degenerates each time the file is opened (decompressed) and closed (compressed), so that over a period of time your image will lose color and clarity. The TIF is a larger and stable file, and if you need a JPG to send by E-mail, you can open the TIF file, do a "save as" into a JPG file, and send the smaller JPG.

When you name your newly scanned file, designate it as the original scan, e.g., MarySmith-orig-scan.tif. Then make a copy of that file and call it something like MarySmith-edit.tif. That latter file is the one you are going to restore. Once you are done with the restoration and do not have any need for the original (which you should keep for comparison and also in case the edit copy is damaged or you make a huge mistake and have to start over), it can be kept or deleted, whichever you like.