captainsolo said:
The biggest thing is how in the heck did Douglas Slocombe shoot without a light meter? ;)
In all honesty, shoot enough film and it really becomes second nature. After a couple years in film school, we could eye the aperature setting pretty well. A friend and I even shot a reel of 16 without a lightmeter and it turned out really well.
But I will say shooting a reel of 16mm one afternoon with your friends and shooting a large budget film are two different things. I know I wouldn't feel comfortable not making sure.