Scanning photo basics

Learn the best methods for scanning a photo into your PC. This guide will get you up and running with your scanner and show you how to get the best-quality results for scanning and sharing your photos online.

So you finally bought yourself a scanner and have big plans to scan treasured photos and share them with your friends and family online. What do you need to know?

This guide will get you up and running with your scanner and show you how to get the best quality results, plus tips on how to share your photos on the Web or over e-mail. Before we dig in, let's review how a scanner works.

A scanner works by passing a bright light across an image. The light from that image reflects on rows of mirrors. The mirrors send the light to a charge-coupled device (CCD), which converts the light to voltage. From there, the voltage is sent to an analog/digital converter, and then to your computer for storage and editing.

The quality of the CCD determines the quality of the scanner. The CCD acts as the main gateway between the photograph on the scanner bed, and the file stored on a computer's hard drive. The image brightness, colour depth, and clarity depend on the accuracy and number of sensors in the CCD (as well as the brightness of the scanner lamp).

How to choose a scanner
When it comes to judging specs, be sure to read the box carefully. Some manufacturers quote the interpolated resolution rather than the optical resolution. The former conjures up pixels where none exist, by mathematically approximating the pixel value based on its neighbours, while the latter figure represents the actual number of photo-sensitive sites on the sensor.

Optical density can also be a tricky spec. It's a measurement of the range of tonal values a scanner can capture, on a scale of 0 to 4.0; the closer to 4.0, the more detail you'll see in the highlights and shadows. But there's no standard defining the scanner settings with which the measurements are taken, so we can take the manufacturer's quote as only a rough approximation.

The breadth and depth of scan controls, as well as the software bundle, can make a huge difference in your scan quality. For instance, to get the maximum tonal range, you should perform colour and exposure adjustments at scan time whenever possible rather than during post-processing -- in Photoshop, for example -- to minimise image degradation.

Similarly, if you have a ton of photos to scan, you definitely need a driver with good batch-scanning capabilities and well-designed film holders. In addition to basic apps, most scanners come with some sort of additional software, even if it's only a modest imaging program such as Adobe Photoshop Elements.

Take some time to read about your scanner with this information in mind.