I’ve experimented with creation of image files as clones of hard drives and partitions. Generally my results have been pretty poor. I have no problem creating the image file and sending it to external storage such as placement in a folder on an external hard drive. But when I attempt to reinstall the image file in such a case as using that file for a backup of a partition or entire hard drive it never wants to install properly. Actually I had never successfully been able to do this. For this reason when I need to copy for backup purposes hard drive information I generally use a straight file to file copy utility.
In cases where I have an entire deleted partition I then use a powerful third party data recovery tool for deleted partition recovery. Partition recovery software of this kind is designed to quickly scan even the largest hard drives and partitions creating a list of all named data and deleted data on that grouping of hard disk drive sectors.