ISO for video camera!
Posted 27 February 2007 - 01:05 PM
To find the ISO of a camera video: lighting a gray cart 18% with a spot 3200K
Frame the gray cart and put the iris in auto mode....
Look the result ex: f/2.8
Take a light mesure with a photometer (incident one)
Look the result... and shift the ISO dial until finding the f stop of the camera
Read the ISO value
I't is good and safe???
Posted 27 February 2007 - 05:37 PM
Posted 27 February 2007 - 06:02 PM
The auto-iris on video cameras is quite often set too high, putting a gray card well above 50 IRE. You're better off using a waveform monitor to set the desired brightness, probably closer to 45-50 IRE depending on the look you want. Without a waveform monitor you can use a properly set up monitor and set a correct exposure by eye, cross referencing the gray card and other subjects until you come up with a sensitivity that's consistent.
But as already stated, the effective ISO of a camera can vary with the light level, and "proper" exposure may be determined by the highlights as much as the midtones. Use the effective ISO as a rough guide for lighting only; don't set your exposure by it.