Comparative Test: HP Officejet Pro 8500 vs.Samsung CLX-3175FW: Quality Of Scans
Both AIOs have a CIS-scanner. These scanners have less depth of field than CCD-scanners. Power consumption is less, however.
Scan of B/W text
The more contrasty the template, the easier it is for the recognition program (OCR software) to decipher the text.
Both scanners use the same template, but the result is diverging distinctly.
Scan of colors
If you put emphasis on correct rendering of colors, you need a high-end scanner. Samsungs AIO adulterates colors, easyly visible in the red area below left, HPs scan is ok.
Depth of field
If you want to scan two adjacent pages of a magazine or a book, a CIS scanner is of little help. It cannot scan a focussed picture if the template isn´t flat on the scanners glass.
The lab tests this with a watch. The dial-plate is located a few millimeters above the scanner glass. Both AIOs cannot read the dial-plate focussed.
If you want more depth of field, you need a CCD-scanner.
More information about CIS and CCD can be found in our article Vergleichstest Fotomultifunktionsgteräte (in German only).