hi friends, There are many reason why photos or videos gets corrupted or lost from sd cards.It may be due to human error, damaged file system, formatted or corrupted SD cards, accidently pressing “delete all” button of digital cameras, emptied trash bin or abrupt shutdown of the system and various types of system failure. In order to recover data from corrupted, formatted, deleted or crashed sd cards we can use many free trial versions available in the market. Mac undelete from sd card software supports all versions of mac operating system and recovers data from lost, corrupted, formatted missing or deleted photos and videos from USB flash drives, crashed memory sticks, external hard Drives, SD cards, pen drives or removable disk drives.You can check the link