Scanners buying guide
Want to digitise all your photos so you can add them to Flickr or store your important documents electronically? With a good scanner you can get high resolution copies of everything, so you'll never have to dig through paper archives again.
What resolution do you need?
The most important thing to look for in a new scanner is the resolution. Just like on a TV, the higher the resolution, the better the image. It's measured in dots per inch, or DPI (see Glossary), and tells you how sharp a scanner's output will be.
Separates or All-In-One?
You can buy a scanner as a separate peripheral, but many also come built-in to printers, known as All-In-Ones. All-In-Ones can operate as a photocopier too - just press a button and the image in the scanner is scanned and replicated using the printer part of the device. You may not even need to attach it to a PC in order to do this.
What's a networked All-In-One?
The most expensive All-In-Ones may also have a networking port or Wi Fi built in. If that's the case it means two things. First of all, you can access the scanner from any PC connected to your home network without connecting it directly via USB. Secondly, a networked scanner will likely have sharing options, so you can scan a picture and email or post it to Facebook or Flickr without using a PC.
Scanners don't just work with paper. Many come with adaptors for scanning photos, negatives and slides too. These are great for uploading high resolution images from your old albums on to photo sharing sites.
- DPI/PPI - scanner resolution is measured in dots per inch, or DPI, and sometimes as pixels per inch, or PPI. This is usually written down as a multiple such as 2400x4800, which describes the number of horizontal dots by the number of vertical dots per inch square in the final digital image. The higher the DPI of a scanner is, the more accurate, crisp and clear scans should be, although it's important to point out that DPI and PPI numbers don't reflect the real resolution of the camera in the scanner, which is always much lower. Software is used to increase the size of the final image.
- OCR - many scanners come with Optical Character Recognition (OCR) software. This means your PC will be able to decipher text on a scanned-in page, so that it can be searched through or cut and pasted as if you'd typed it into a word processor.