FileSystemWatcher.Filter - before or after the buffer?

I am working on a project with a very large number of files that change and are created / deleted. There are some problems with filling the internal FSW buffers and expanding them.

I found inconsistent information on the Internet that the ".Filter" filters are filtering out BEFOREor that AFTERdetected changes are added to the buffer. If in fact, after a single FSW with event sorting subsequently may make more sense.

Does anyone know here who knows this?

Thank.