Quote:
HK films didn't fully start using sync sound till i believe the late 90s


Sorry, am in an annoyingly anal/correcting mode today but...actually, quite a few Hong Kong films were sync sound for a time (see samples from the Shaw Brothers/Celestial collection like THE KINGDOM AND THE BEAUTY from the 1950s and DREAM OF THE RED CHAMBER (the Brigitte Lin and Sylvia Chang version) from 1977/8 *before* dubbing became the norm (and reached its height in the 1980s through to early 1990s) in Hong Kong cinema.

Traced/Put another way: it seems that Hong Kong movies were often synch sound early on when they were filmed in studios and one language. But as it became the trend to film on location and for there to be two language track options (i.e., Cantonese and Mandarin) per movie, dubbing gained popularity for convenience's sake until the latest swing back in favor of sync sound.