Apparently about 16hrs. This is from the 550 manual, and it shows this same info on the 650 manual. However, the 650 records at approx 50% higher bitrate.Do you know the approximate length (in time) the 64GB card will hold?
I am not sure exactly how much time I had recored the night and day it kept recording nearly constantly, but it was over 10hrs worth, and it had only used 20GB. What causes this variations suggesting I could get 30hrs worth is that a lot of that was recording nothing but the black night, therefore very little info is actually being recorded, requiring less data.