Choosing and Using a Scanner

Buying a scanner.

The most useful scanners are the "flat bed" type.  You can use them for scanning collections of flat items (old family photos, pages from books, newspaper clippings, the contents of your wallet).  For scanning photographic prints, look for a scanner with a resolution of at least 600 dpi (dpi = "dots per inch"). Typical scanners in the $50 - $150 range meet these requirements. Scanners come with their own software that you must install. Many also come with special software that can scan printed material and convert it into editable text for use in a word processor.

If you have 35mm slides that you'd like to scan and convert into prints, or if you have negatives (black-and-white or color) that you'd like to print, look for a scanner that has a transparency attachment.  This is a device in the top cover of the scanner; it contains a light and a thing to hold the slides/negatives in place. For this application, look for a scanner with a resolution of at least 1200 dpi. Suggested model: Epson Perfection 4870.

Using a scanner.
1. Turn on the power to the scanner, if it has a power switch.
2. Launch Paint Shop Pro or any other photo editor.
3. Click on the little picture of a scanner in the top toolbar (OR, click File => Import => TWAIN =>Acquire). 
4. Place the item(s) to be scanned on the scanner glass, face down.  
5. Set the scanning resolution, which can usually be set to 75, 150, 300, 600 dpi or higher (dpi = "dots per inch"). The higher the dpi, the finer the detail that will be captured, but the larger the picture will appear when viewed in email or on the Web, and the larger the file size will be when the image is saved (taking up more disk space).   If you plan to print the image later, perhaps after some digital manipulation, set to a resolution of 300 dpi.  You can always reduce the image size later for email or Web display.  To create a screen image that is the same size as the original, set to 75 dpi.  For scanning slides and negatives, set the resolution to at least 1200 dpi.  
6. Click the Scan button on the scanner control screen.
7. Once the scan is complete, pull down File => Save As... and navigate to the place where you want to save the image. Select "JPEG" from the "Save as Type" pop-up menu.  Click Save.
8. Scanned images can be manipulated using any photo editing program, like any other image.

Separating a composite photo scan into individual photos
 Often, when scanning small photographs on a flat-bed scanner, you can save time by scanning several photos together.  Some scanners will automatically separate the photos, but some simply give you a composite image that has all the photos in one large image. To separate them, here's what to do:
1. Open the composite photo with Paint Shop Pro. (For practice purposes, you can use "OldPhotos.jpg", in the Example Pictures folder on the CD-ROM). 
2. Select the  tool in the side toolbar and stretch out a rectangular area over one of the individual photos.
3. Select Edit --> Copy.
4. Select Edit --> Paste as New Image.
5. Select File --> Save As... , click on the "Save in" menu and select the place where you want to save the image, select "JPEG" from the "Save as Type" pop-up menu, and finally click Save.
6. Repeat for each photo.
                                                       (c) Tom O'Haver (toh@umd.edu), Revised February 2005