Camera Memory these days is seen as a hard drive, and so you should be able to recover it fairly easily using free tools, such as smart Recovery. The most important thing is not to use the drive for anything else. Just like with a hard drive, even though it tells you the data is gone, it actually isn’t until the space on the drives where the files are located is overwritten. When you initially delete a file or folder, it just removes the reference to it, not the file itself. Only when the space on the hard drive/usb drive is overwritten is the data deleted. Though there are programs like SpinRite that can recover such files as well, so long as it hasn’t been very long since the files were overwritten.
Recovering Files off Flash Memory