3nh / Sineimage X-Rite White Balance Chart White Balacing Test Chart YE0178 for shading measurement

The test chart consists of a blank film between two glass panes.

The test chart is designed for shading measurement under the same lightning conditions as other transparency measurements.

It is possible to perform shading measurements on illuminator (LG2, LE6) without any chart. But then lightning conditions are different to other measurements with test transparencies. By using a test transparency the light intensity of an illuminator changes.

This is caused by two superimposed factors
a) the filter effect of the film and glass (25% light absorption) and
b) the light remission of the transparency ack in the illuminator

While factor a) is predominat with th LG2, the remission factor b) is predominant with the lightning sphere LE6, i.e. the light intensity rises significantly when a test chart is inserted. To carry out shading measurement under the same lighting condition as other measurements the use of the YE0178 is essential.

Definition of white shading or white level uniformity

Determination of maximum white level variations in various areas of the picture, when the camera is directed at an evenly illuminated test chart.

The YE0153 is designed for evaluation of the halftone reproduction of electronic cameras. Two 11-graduated counter current gray scales are arranged on a gray background (D=0.75), the gray scale being graduated logarithmically.

Related to the densities of the gray scales: gamma = 0.45

Related to the reflectance values (brightness): gamma = 2.2 , that being exactly the reciprocal value of gamma = 0.45.

The output signal of an optimally gamma-corrected camera yield two 11-graduates counter current linear step signals. The contrast range of the gray scales is 40 : 1.

The values of the 11-graduated gray scale are as follows:

The density values are based on BaSo4 = 0. Two black fields and a white field are located between the gray scales, the density of the black filed is D > 2.4 (reflectance < 0.5 %). The density of the white filed is D = 0.05 (reflectance = 89.9 %).

18% grey card