How to Get Top-Notch Scans

Scanners are a great way to transfer photographs to your computer, but getting the best results requires both skill and experience. The skills aren't tough to learn, though, and the experience can be fun.

Difficulty: Moderate

Instructions

Things You'll Need:

• Glass Cleaner
• Scanner
• Computer

1. If you're using a flatbed scanner, make sure the glass is clean and unsmudged. Use a glass-cleaning solution to get it as transparent as possible.

2. Consider your source material. Is it as sharp as possible? Scanning magazine photos will likely result in ugly moire' images with murky patterns in them.

3. Find out the resolution at which you will be using the final image. If it's going to be displayed on a computer screen, that's 72 dots per inch (dpi). An inexpensive ink-jet printer might be 90 dpi, while a color laser printer might be 300 or 600 dpi.

4. Set the resolution for your scan to be at least 1.5 times the resolution of your final output. For example, for a 90-dpi ink-jet printer, you'd set the scanning resolution to be at least 135 pixels per inch (ppi). Scanning at a higher resolution will produce large graphics files that make demands on processor speed and the hard disk, though, so don't set resolutions higher than necessary.

5. If your scanning or image-editing software provides a tool for adjusting the luminance (as opposed to simple brightness and contrast) of your images, then take the time to learn how to use it. This will provide much more precise control over what we think of as the brightness and contrast of an image.

6. Whenever possible, plan to scan your image at its final output size. If you have to change the size of an image later, the image-editing software will introduce fuzziness as a consequence of adding or removing pixels (called interpolation).

7. Almost all scanned images (and digital photos) can benefit from a certain amount of sharpening to compensate for fuzziness that is introduced during the image-acquisition process. The tool for this is called an Unsharp Mask (see Tips), and the best way to learn how to use it effectively is by trial and error, so have fun.

Tips & Warnings

• A good general tutorial on luminance controls can be found at www.scantips.com.
• Always make the Unsharp Mask step the last thing you do before an image is ready for printing or posting online.

[sboals]

on 5/5/2007 Some good info on scanner features at www.scanguru.com