Scanners - An Introduction

Flatbed or Film Scanner

Flatbed scanners are primarily designed for scanning prints and many can also be used to scan film using film and slide adapters. Film scanners can only scan film. Generally they offer better quality and a higher dynamic range than flatbed scanners and are the preferred option when high quality output is desired.

As film contains significantly more information than prints, if film is available it is preferable to scan film in preference to prints.

What You Should Know

Resolution

Scanners have a Dots Per Inch (DPI) rating which describes their maximum resolution. The higher the scanners resolution, the greater amount of detail collected from the film or print by the scanner. Resolution directly relates to the largest prints that can be produced and the level of detail contained therein.

Dynamic Range

Dynamic Range ratings describe how many levels of gray that the scanner can detect.  The higher the number the better. Film is generally accepted to have a dynamic range of 4. Accordingly, a scanner with a dynamic range of 4.2 or high will provide the best results.

Bit-Depth

Scanners create images with a number of bits per pixel. There are 3 colour values for each pixel (Red, Blue & Green). The number of its per pixel is most commonly in the range of 8, 12, 14 or 16 bits per pixel. The resulting images have 24, 36, 42 or 48 bits of information per pixel. The human eye cannot distinguish between a 24 and 48 bit image, but the additional colour information produces prints with more accurate colours and is very useful if the scanned images are to be manipulated.