You don't need a fast frame rate. At normal frame rates tour pros start their lower body movement for the downswing 2 to 4 frames before their arms start.
As with many things for golf there may be some who do this 'naturally' (before being taught)and if you are one then you're lucky. However it is not only possible but highly likely (given video I have of amateurs greater than 70% probability) that your lower body will not move first in the downswing.