To set the exposure on the Canon C70, first set...

  • ISO to be 800 (native - best for dynamic range)
  • Shutter angle to be 180 degrees (motion blur)
  • F stop to match the desired DOF

Then adjust the ND filter to obtain the desire exposure.

False color is a tool to visually get an indication of exposure. 

From the Canon manual.

ColourDescriptionIRE
 Red White Clipping 99-100%
Yellow Near White Clip 97-99%
Pink One stop over 18% Gray 52-56%
Green 18% Gray 38-42%
Blue Just above Black Clip 2.5-4%
Purple Black Clipping 0-2.5%

Dark grey to light grey is shown for exposures between these values.

To set good exposure for skin tones (target between 55 IRE to 70 IRE - we want the face to be Pink and Green - with no Blue (underexposed) or no Yellow (over exposed).

false colourImage courtesy: Time in Pixels website

 

Using Zebras

Another method is using a Zebra at 50%IRE +/- 5%. 

But I usually like to keep the Zebra at 95% to check for blown out areas.