6 megapixels and no digital camera…

If you go into one of those Kodak one-hour photo concessions in just about every High Street you can get your film scanned onto a CD for a few extra quid per roll. My local franchisee let me in on a secret. If you ask nicely, your outlet can turn the scanning resolution up from 1536×1024 to 3072×2048 which is over 6 megapixels and better than you’ll get from most high end digital cameras. The results seem to be gorgeous. My guy calls this ’16 Base’ but I can’t figure out why. Am I getting higher actual resolution or is the scanner interpolating? Is there a catch?