Why does 'My Files' not explain why my SD card is full

[Android Central Question]

I have an 8 Gb SD card showing 1 Gb free.

I know my SD card is storing some media, but the directories shown in the My Files app do not come close to accounting for the space used. I tried showing hidden files and deleting ".nomedia" files, to no avail.

What's a good app to figure out what is taking up all the space? My Files is not going to cut it. I want to zero in on my large directories.

 

[Rukbat]

File manager apps won't show hidden files or system files (unless the phone is rooted). Even apps that show where all the space is being taken won't.