
Select 'Folder 1' and, if you want, 'Folder 2'. Just to make sure that you do not select any file.
Press Ctrl+U or select Batch Convert from the menu. You'll see in the list 0 (zero) files.

Also, if you want, select some folders (with photos inside) an one-two files. You'll see that in the Batch Convert only files appear.
The selected folders are invisible for the Batch Convert engine.