Quick format vs. Complete format
There are two significantly different types of the format procedure.
After using one of them, data can still be recovered, but after applying the other - data is unrecoverable.
Most cameras use the normal mode of format (quick format) after which you can restore your data.
However, in Canon PowerShot digital camera series there are both the normal mode and the "low level format" mode.
If you use "low level format" (complete format),
all the data on the memory card will be deleted irreversibly and any data recovery software would then be useless.
Nevertheless, Canon digital cameras use the normal format mode by default.
If you formatted your memory card in the normal mode, the data recovery process doesn't differ from other cameras.
If you used the "low level format" mode, you cannot recover anything because all your data is gone and there is nothing left on the memory card.
If you have formatted your device (e.g. a hard drive) by means of Windows (Right click My Computer -- Format),
the result of recovery depends greatly on the used format mode.
If you check Quick Format from the Format options, then the formatted data can easily be unformatted
provided that new data has not been written on the device after format.
However, the Quick format mode is not set by default; if you don't apply this mode nothing can be recovered.
There is a rule of thumb that for each new file written to the disk you lose one of the original files.
So we recommend you stop using the device as soon as you decided to recover data from it.
Quick format vs. complete format in different Windows OS
Complete and quick format are different in different operating systems.
In Windows XP complete format and quick format are the same - neither of them overwrites all the data, and both are recoverable.
Windows Vista and Windows 7 quick format doesn't overwrite user's data while complete format does overwrite data,
and is thus not recoverable.
Things get even more complicated in Windows 8.
Quick format applied to a Storage Space in Windows 8 is
no less destructive than complete format.
Despite it is very quick and doesn't physically overwrite user's data,
some important Storage Spaces tables are destroyed in process, making recovery much more complex than in case of a regular volume.
This is due to Storage Spaces specifics.