TE223 A Gray Scale Test Chart Reflectance is designed for evaluation of the halftone reproduction of electronic cameras. 

 

Two 13-graduated counter current gray scales are arranged on a gray background (D = 0.75), the gray scales being graduated logarithmically. Related to the densities of the gray scales: gamma = 0.45, related to the transmission values (brightness): gamma = 2.2, that being exactly the reciprocal value of gamma = 0.45. The output signal of a optimally gamma-corrected camera yields two 13-gratuated counter current linear step signals.

 

The contrast range of the gray scales is 200 : 1.

 

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

Step	Density	Reflectance in %
1	0.05	89
2	0.13	74
3	0.21	62
4	0.30	50
5	0.40	40
6	0.51	31
7	0.63	23
8	0.78	17
9	0.95	11
10	1.15	7
11	1.41	4
12	1.77	2
13	2.35	0.5

 

The density of the white field between the gray scale chart is D = 0.05 (reflectance = 89 %).

 

Keywords: Gray Scale Test Chart, grayscale chart, grayscale test chart