What Is a Scanner?
A scanner shines a light on a document (text or graphic) and records a lot of dots. If the image is black and white, each dot is either black or white. Most scanners record 256 shades of each primary color. That takes 8 "bits" for each color. You'll often see options of scanning in "24-bit" color. After those dots are converted to electrical pulses, they're converted into a number by "digitizing." The point of bringing up the math here is that the files grow really fast as we gather more information about each dot we scan.

The user has a wide choice of resolutions, and the arithmetic to figure out how to get the best image would be a challenge for a math major. If you look at some of the explanations in the links section of this article, you'll see that you have to convert scanned resolution (in "dots per inch") to printed resolution (in "lines per inch") or screen resolution (in total dots per screen). A general guideline is that if you scan at resolutions that can't be output by your screen or printer, you will only get a slightly better looking image, and you might take up a LOT more disk space.

I've seen a number of cases where genealogists list two different locations in the same census citation. If your scanner is a 600 dpi scanner and you scan an image at 9600 dpi, the computer does something a lot like what those genealogists do—it connects the dots with ones it makes up. From an information-honesty perspective, I don't like the idea of creating records with data I just make up or that a machine makes up for me. I'd suggest that you not exceed the rated resolution of your scanner when creating historical records!

Name Two of Them
There are a number of different manufacturers making scanners, but in my opinion, the only ones to think about buying are the flatbed scanners. Hand-helds are a little harder to get good images from. There is a pen-type scanner that will read lines from documents, but I still prefer making copies and scanning whole sheets. There are some big differences in price, but these days you can buy a better scanner for under $50 than you could buy for $1,000 in 1990. The biggest differences in any two scanners these days are the price and the connection method (parallel, SCSI, and USB).

When It Works, What Does It Do?
If you have a printer and a scanner, you can "close the loop" of information flow between digital and paper. Scan information, and it's instantly digital. Print it, and it's instantly paper. You can scan documents such as land records or birth records, as well as photographs of people and places. It's also possible to use a scanner and printer as a "plain-paper fax" to support fax functions. You can even use a scanner to scan objects, if you desire.

What's the Downside?
There aren't many downsides to scanner use. Of course, if you get a scanner, you're going to want to have a lot of free disk space to put all of those pictures on. You'll have to learn to choose which images to keep and how to let go of the other ones—a big challenge for a genealogist. In times past, there was a problem with complicated setup, but that's much easier now.

How Do I Know If It's Not Working?
I only see two kinds of problems: bad connections and wrong settings. As a rule, if you set up your scanner properly, it will keep working all the time, but occasionally I have the scanner turned off when the PC comes up, so it can't find the scanner. When that happens, you have to restart the PC.

If you scan a document with the wrong settings, you can usually either re-scan it or change the image in a graphics program.

What If I Change Computers?
Scanners come with three different pieces of software: a device driver that tells the computer how to talk to the scanner; a scan manager program that actually controls the scanner from the computer (in which you choose the resolution and picture type); and some special edition of a graphics program to catalog, print, and clean up the images you make.

If you change computers, you will want to reinstall the drivers and scan manager software. Be sure you can hook it up; some PCs don't have the same connections. This is especially true with SCSI connections.

What's the Genealogy Tie-in?
Converting pictures of family members and images of historic documents to computer files gives you the option of linking those files to your genealogy records about those people, and of e-mailing them to your relatives and colleagues.

Link Me Up (More stars is better)

• ZDNet Reviews ***
  Great product evaluations, tips, and explanations for beginners.

• Scanning Overview ****
  A good explanation of the basics of scanner technology.

• MySimon ****
  A terrific site to learn about all types of products. In 20 minutes, you'll know the differences in the products available and which brands and models you prefer.

• Scantips ****
  Just like its name, lots of scanning tips, including a method for getting the best pictures.

What Else?
Some scanners support transparency adapters (a backlit replacement for the scanner cover that lets you scan slides and transparencies; this costs about $150) and sheet feeders (a mechanical replacement for the scanner cover that lets you scan a stack of papers; this costs about $150 as well). One other function of scanners is to convert paper documents to text, using a process called Optical Character Recognition, or OCR.

Next time, we'll cover image file formats.

Beau Sharbrough is the president of GENTECH, the founder of the GENTECH and FGS Web sites, and a founder of the Lexicon Working Group. He would like to hear from you at beau@sharbrough.net, but due to the volume of e-mail received, he is unable to answer every e-mail message received. Please note that he cannot assist you with your individual computer problems. Visit Beau's Web site for information about speaking engagements. Beau is the father of two college-age girls and is another insufferable graduate of Texas A&M University.