is an activity performed by a device that optically scans images, printed text, handwriting, or an object, and converts it to a digital image. Common examples found in offices are variations of the desktop (or flatbed) scanner where the document is placed on a glass window.
How to be sure that the scanner (Nikon Coolscan 4000) focuses correctly and if not, how can I manually focus it using Vuescan?
Other equivalents are welcome as well. I want this information to know what scanners I need to look at or at least to have the ability to determine if a scanning service will suffice my needs.