in practise it only works to sync multiple camera's and even then it won't be accurate to the frame.
clocks can/will start to drift after a few minutes so it won't be frame accurate.
So however usefull for getting the shots approx. close. not realy the best solution for audio syncing.
The easiest solution for syncing dual system sound is the stand alone program "dualeyes" or the plugin "pluraleyes"
at 149$ realy worth the investment in my opinion.
thanks for the reply, the workflow of pluraleys/dualeyes is still a bit of a hassle...
Horita makes a cheap timecode generator which can feed timecode signal to the mic in on DSLRs, only Avid and Final Cut Pro can read this auido TC...
guess i'll just stick to clapperboard