Stock Rating

[Wally]

How much do you usually overexpose your stock by? I've read that many cinematographers rate anywhere from 1/3-2/3 over than the recommended manufactures speed.

Though I've learned that a 1/3 of a stop over or underexposed isn't really noticeable to the eye. I usually cant see a difference until 1 stop. So do you really get a difference in blacks when its printed from 1/3 to normal?

 

[David Mullen ASC]

Well, 1/3 is better than nothing, but it's within a margin of error in exposing, i.e. even if you rate the stock 1/3 of a stop slower, it doesn't always mean you'll end up with a consistent amount of extra density. But it's still better than nothing. It's really more of a hedge against accidental underexposure more than it is a method of getting extra exposure all the time.

2/3 of a stop overexposure is what I usually do unless I don't have enough light.

1-stop over isn't really practical most of the time, plus at some point, you end up getting a softer image because either you are shooting too wide-open or there isn't enough depth of field for your focus-puller. So there are laws of diminishing returns. Plus at some point, you might as well just switch to the next slower speed stock.