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Let the scanner warm up for half an hour before you use it.
   technofile
Al Fasoldt's reviews and commentaries, continuously available online since 1983

Digital imaging on the cheap, Part 3: Scanner tips you won't find in your manual


Oct. 22, 2000
   
What the jargon of image scanners really means
   
By Al Fasoldt
Copyright ©2000, Al Fasoldt
Copyright ©2000, The Syracuse Newspapers

   Scanners turn photographs and drawings into digital images. But they won't make GOOD digital images unless you do a couple of simple things.
   You might think it odd that the first two steps have nothing to do with scanners. But just as a new pair of eyeglasses won't do you much good if they're constantly dirty, a spiffy new scanner won't be much good if your computer can't show images very well.
   So the most important step is to make sure your computer knows how to show realistic colors. Whether you're using a Windows PC, a Macintosh or a Linux computer, the approach is the same:  Adjust the display settings so that the computer can show at least 16-bit color. (This is called "thousands of colors" on a Mac.) Even better is 24-bit or 32-bit color (called "True Color" on many computers and "millions of colors" on a Mac).
   Next, be sure you're using a display resolution that's high enough to view your scans. If you have a 15-inch monitor, a resolution of 800 X 600 pixels is about as high as you should go without making things hard on your eyes. If you have a 17-inch monitor, 800 X 600 might not be high enough. Change it to 1024 X 768 if possible. If you have a monitor larger than 17 inches diagonally, try 1200 X 1024. I run 1600 X 1200 quite happily on my main computer. Don't be afraid to try that setting if your graphics card supports it.
   Ready for the good stuff? Here goes.
   Clean the scanner glass with Windex before every important scan. (There are other glass cleaners that problably work fine, but Windex is what I use and it is safe.)
   Let the scanner warm up for half an hour before you use it. Critical parts expand slightly and get closer into alignment when the scanner is warm. Do a few test scans (and delete the resulting images) to finish the warm-up.
   Scan each image at two resolutions, one low enough for computer screens and the other high enough for printing. The computer-screen images should be scanned at 75 or 100 dots per inch. The ones you want to save and print on your fancy color inkjet should be scanned at a resolution of 300 dots per inch. (WARNING: Scanning a normal-size photograph at very high dots-per-inch settings creates extremely large files. If you want to scan at 600 dpi or higher, start with a wallet-size photo and check the resulting file size before you scan anything larger.)
   Scan a treasured image at least twice and save the one that looks better.
   Always save (or "export," if your software calls it that) your scans in a "lossless" format. If you prefer uncompressed TIFF files or Adobe Photoshop (PSD) files, fine. Otherwise, save or export in Windows BMP format. BMPs are universal and are the least complicated of all possible methods of saving images. (That means a corrupted BMP file has a better chance of being rescued than a corrupted TIFF or PSD file.)
   Don't use a JPEG (also called "JPG") version of a scan for editing. Repeatedly saving edited versions of a JPEG image ruins the image quality.
   Scan only the image. If your image is smaller than the maximum size of the scanner image area, use the scanner's built-in software to crop the scanned section down to the image size. Leave no more than a tiny border of space around the image.
   Use the "black and white" setting to scan drawings and sketches (unless, of course, they are multi-colored images). This makes a much better scan and keeps the file size down.
   When you're finished scanning, get rid of all the temporary files your scanner creates. That means you should delete all unwanted images from the scanner's own "desktop" and then empty the scanner's trash can (If it has one) and the computer's own trash can . This applies to both Windows and Mac computers. You can easily lose 100 to 300 megabytes of disk space after spending a Saturday afternoon at the scanner, so reclaim as much as you can.
   Next: Choosing photo-quality paper for your inkjet printer.