Sometimes developers request you to change log level settings to obtain more detailled logs, they need to address the errors they have etc. more efficiently.
In Central Administration, under Operations > Event Throttling
you have to change
"Least critical event to report to the event log " and "Least critical event to report to the trace log " settings in order to achieve the desired logging levels.
But I came across a few situations where it did not apply the logging level although you change the settings!
If you encounter such situations, just restart the Windows Sharepoint Services Tracing service and its done!