Complex sentence: Since the cards are controller-less, cameras and card readers must perform wear leveling and error detection themselves, and they normally hide the portion of the memory which stores this information (among other things) from higher-level access.
Split into simpler sentences: Since the cards are controller-less, cameras and card readers must perform wear leveling and error detection. They normally hide the portion of the memory which stores this information (among other things) from higher level access.