Meet The Gaffer #28: Using A Light Meter - Part 1

Director of Photography, Tomas Tucker, shows how you can determine the real ASA/ISO of your camera by using a light meter and white card.
I think Zahi has discovered a mistake I made in my presentation. At about 5:55 into Part 1, I mention that if the camera’s f-stop reads f/4 and the light meter reads f/2.8, your camera is slower than 400 ASA. This is incorrect. You need to increase the ASA on your meter to 800 to get it to read f/4. DON’T TOUCH THE F/STOP ON THE LENS! Your camera is telling you what f-stop the meter should be reading and you adjust the light meter’s ASA ’till you get there. I misspoke. I should have said, “Your camera is faster and the native ASA is 800”.