However a deep scan can only identify the first extent of a file (as subsequent extents have no file signatures). If the files are fragmented, as they most likely are in large files, then recovering a playable file is impossible.
That depends upon the Recovery software.
I had an HDD with several partitions that became Unallocated Space and RAW Data.
After trying many freeware utilities I tried Commercial recovery software costing $69 which recovered all my files.
These files included several 6 GB Macrium Partition Image backup files,
But the Macrium Application check-summed them and found they were all corrupt and unusable.
I continued looking for Freeware and eventually had perfect success with
http://www.lazesoft.com/download.html
Lazesoft Recovery Suite 3.5 Home Edition (Free)
The original 6 GB files each had about one dozen fragments or extents before they went missing.
Lazesoft found each fragment and joined them up in the correct order.
The Commercial software recovery attempts were each the same size as the Lazesoft successes,
so either the fragments were put together in the wrong order,
or more probably it started with the correct Logical Block Address for the first fragment,
and having saved that it "saved" the contents of all the sectors immediately afterwards, reading the contents of fragments of unrelated files.
I do not know how Lazesoft does its magic, but I am thankful for it.
It may work for you.
N.B.
Data Recovery => File Recovery is faster
Data Recovery => Partition Recovery is more thorough but takes longer.
Regards
Alan
P.S.
I see that until you pay for it R Studio is restricted to recovery of 64 kByte files,
and anything larger will ONLY be viewable in DEMO mode with no opportunity to discover that all the fragments in your 22 GB ISO's are out of sequence and unusable.
There is no cost and no restrictions on
Lazesoft Recovery Suite 3.5 Home Edition (Free)