Deep Scan should be used when lost photos and videos have not been found during Quick Scan. During this procedure, R‑Photo deeply analyzes all data on the disk including parsing information about files and searching for files using their file signatures . 

While Deep Scan starts, additionally found files are added to the corresponding tabs automatically. All file search settings and marking will be cleared.

Deep Scan is also greatly improves estimations for chances of successful file recovery .

To start Deep Scan c lick the Deep Scan button on the Files tab.

Deep Scan progress appears at bottom of the the R‑Photo window.

Deep Scan in Progress

Depending on your hardware, scan time may vary, even within the same scan process, and may be quite lengthy for large disks. Deep scan may be paused then resumed it by clicking the Resume scan button.

R‑Photo stores the scan information for a scanned storage device or its disk(s) and loads it automatically once the storage device is connected again.

It also warns the user that the scan information is obsolete if it's seven or more days old and deletes it after 30 days.

If R‑Photo finds a previous partition with a different file system, it shows a special message:

Deep Scan - two partitions 

You may switch to the second partition and recover files from it:

Deep Scan - second partition