Use the Sekonic Exposure Target II (JQ67) for calibrating cameras and meters, especially Sekonic 758DR and 758Cine meters.
This 25 patch test target gathers more information about a camera's exposure characteristics than other test targets. It consists of two sides: an 18% Gray Card used to custom gray (white) balance digital cameras before profiling; and a Profile Target consisting of a central 18% gray patch that is surrounded by 24 patches arranged in 1/6th stop values that are successively brighter and darker.
The Exposure Profile Target II offers faster, more accurate testing as it requires only three shots to gather a wide range of exposure data from the camera's imaging system. The first shot is made at the normal, metered exposure determined by a Sekonic L-758DR. The second shot is made at -3EV below the metered exposure and the third shot at +3EV above the metered exposure.
The Exposure Profile Target II is fully compatible with the free Data Transfer Software and L-758DR and L-758Cine to profile your camera and lens combinations. The result is total exposure accuracy.