I have one of those, and it has a series of patches centered on 18%. (So nominally the card is 18%). But I believe the way you use it attempts to "place" the exposure on 18%. You meter with incident light and shoot the card with a camera. Then you analyze the results.
Originally Posted by benjiboy
You'll be pleased to know that the incident light reading does NOT agree with a spotmeter reading off 18%. It agrees more closely with a spotmetering off the 12.7% patch!
Last edited by Bill Burk; 02-09-2012 at 08:08 PM. Click to view previous post history.