Mac Data Recovery
Mac Data Recovery Guru is a highly developed and sophisticated app that will open a drive (or camera, or generally anything that gets mounted in OS X as a volume or disk) and read it as a raw device, or a raw data stream. It then reads the entire thing, and as it’s reading it’s searching for file patterns that are found in certain file types, or for other kinds of patterns such as ASCII text. As it does so it outputs the results as a coherent list of recoverable files on the drive, which are presented to you in a window which is exactly the same as the column-based view that you probably use to browse through your regular files in the Finder sometimes. This is making it look easy. Behind the scenes it’s jumping through all kinds of hoops to get you this info. But it works well. You can even get live real thumbnail previews of the files it’s finding while it’s scanning through your drive with the free demo. If you’ve lost any files or other kinds of data that you want back, even after formatting a disk and then using it again for a few months or sometimes even years, this is your best shot at getting them back.
(Note: We’re so passionate about Mac Data Recovery that we have made an entire sister-site dedicated to it.)