PNG Test Card
bright (lower) row of colored squares are (left-to-right): 255R and
255G [100% Yellow in
CMY system], 255G and 255B [100% Cyan in CMY System], 255G, 255R and
255G [100% Magenta in CMY system], 255R, and finally 255B.
gray scale bars range from 0 (100% Black) to 255 (100% White). The
black square has a letter "B" at RGB 11,11,11 in it; the white square
has a letter "W" at RGB 240, 240 240 in it. Depending on the brightness
characteristics of your monitor, you may not see one or both of the
letters. This target tests the ability of your system to reveal detail
in the extreme dark and light parts of an image.
third row of vertical stripes of varying width alternate between 100%
black and 100% white.
The background of this screen
has been set to 17% grey (RGB 211,211,211) . Most camera light
meters are calibrated to this as the average brightness in a
scene. Depending on the settings and characteristics of your
monitor , this background may not look anything like a standard
photographic grey card, but it's supposed to.