Comparative Test of 8 MFCs with Fax: Scanquality: Depth of Focus
Scantechnology: CCD and CIS
Disadvantage of CIS-scanners: Out of focus in the middle of an open book.If you want to scan pages of a book, you should know more about scan-technology, before you buy a MFC. Some can scan with high quality, even if the template isn´t straight or fully flat, for example, if you scan a book flipped open. Others can´t.
There are two technologies: CCD (Charged Coupled Device) and CIS (Contact Image Sensor). CIS-scanners are flatter and consume less electric current than CCD-scanners. Their disadvantage: All objects to be scanned have to be exactly plain on the surface of the scanner. If not, the scan is out of focus.
This is a simple test: DC scans a timepiece - the dial is a few millimeters above the scanner´s surface. The dial is out of focus with a CIS-Scanner, CCD-scanners have no problem with that.
Only three contestants work with CCD-technology: Canon Pixma MP830, HP Officejet Pro L7580 and Kodak Easyshare 5300.
