I don't own one as yet, what I'm really looking for is how to find out the number of pixels on the CCD? With cameras it's usually clearly stated but for some reason scanner manufacturers like to play with words.
Hi,
There are 2 measures that can be called resolution.
One is the number of sensor elements (sensels), and if known it can be divided by the physical length of the linear sensor array(s) to get the sensel pitch, or by the length of the scanned area divided by the number of sensels to get the pixels per inch (PPI). A universal scanning software product such as
VueScan will be able to extract the full resolution from an immense list of different devices, it's compatible with over 2100 different
supported scanners (also mentions the maximum PPI, as 'optical DPI'), and will offer the maximum PPI as a preset when connected to the particular scanner.
However, that is only part of the story, because the second aspect of resolution is determined by the optical element(s) involved in most scanners. What really determines the actual opto-physical resolution is the combination of the sampling density
and the optical resolution. That's commonly expressed in cycles/millimeter.
Since many scanner manufacturers usually only mention the PPI of a scanner, it only tells part of the full story. It is possible to determine the actual optical resolution of a scanner with a so-called "slanted edge" target. There are also other targets possible but some of them are not really suited for discrete sampling devices.
Cheers,
Bart