[toni-a]

Last I checked, nobody who does video seriously is recording with built-in mics, even if they're using manual focus (and usually they do) and regardless of the lens. Video mic is usually among the first two accessories they're buying, along with a tripod. (there's a Rode Video Mic kicking around our office, for example)

Only videos I usually do are of my little daughter at home, the built in mic is doing just fine when using other lenses