Lighting and exposing for HD
16.1 An HD camera’s equivalent ASA speed, or ISO rating
I check the speed, or sensitivity, of any HD camera using the same technique I would use when testing a film stock’s ASA (American Standards Association) or ISO (International Standards Organization) rating. Note that the numbers will be the same. When checking a film stock’s ASA speed, I set the camera up facing an 18 per cent reflectance gray card and make a range of exposures, noting the setting on my meter for each one. Then I ask the laboratory to make me a middle of the range one light print. Whichever exposure most exactly matches the tonality of the original gray card, I deem it to be the correct rating for that particular film stock. If I use this ...