D30 (3000K) is similar to incandescent light and a pleasant warm tone. Can be an advantage in defects detection for various materials.
D40 (4000K) rather rare, but is also used in certain defects detection application.
D50 (5000K) is often used in the grafics industry and describes the test conditions for colors. This is described, among other things, in DIN ISO 3664.
D65 (6500K) , on the ohter hand, is used for the visual comparison of colored materials. This is described, among other things, in DIN EN ISO 3668
We developed these color control series based on these standards.
The requirements of the standards mainly include:
- The light must correspond to daylight with a color temperature of 3.000K, 4.000K, 5.000K or 6.500K.
- The light source must have a color rendering index of Ra>90 (for planistar even about Ra 95)
- The environment must have a neutral gray, matt color
- With top lighting, the illuminance must be approx. Min. 2.000 to max. 4.000 lx.
- The colors to be tested are ideally assessed under different lighting situations.
Ideally, the test object is viewed under both light colors. With D65 a gray overcast sky is simulate around noon, with D50 it is more of an evening light because it contains less blue.