3:1 would be an extremely low -- I've never seen a shooting ratio that low in my life. Shooting just 4.5 hours of footage for a 1.5 hour film, for example, is unheard of.

Even a 10:1 shooting ratio was pretty low for indie features in the 35mm days. Nowadays it's not uncommon to see shooting ratios upwards of 30:1 on digitally acquired productions. (Although that number varies a lot with the director.)