So, the CanoScan 8400F can digitize at an optical resolution of 3200dpi and a color depth of 48 bits. Its maximum optical density is a good 3.3Dmax which helps get high-quality scans of negative films. An infrared LED is used when you enable FARE technology in the driver and helps identify dust and scratches in the original for further removal. Three holders for transparent originals of all the standard formats, including a holder for medium-format film rolls, are enclosed with the scanner.



Link: Xbit Labs