CIE Conversion

Change the standard observer and illumination of data sets

CIE Conversion

The CIE Conversion tool converts measurement data into another viewing condition.

Possible tasks can include the presentation of photos in a gallery under incandescent light (corresponds approximately to illuminant A) or displays under exhibition lighting, where the lighting consists of fluorescent light. Another task is to change the illumination and observer angle for the textile industry, where D65 and a 10-degree observer are used as standard.

The Illumination drop-down menu contains the following options:

  • Selection of a standard illuminant: D50, D65, illuminant A or the Equal Energy Spectrum. Typically, printer profiles are created for D50 viewing conditions.
  • Manual input of Kelvin or XYZ values.
  • Emission (Open File): Selection of spectral emissions readings (as CxF3 or text file) of a specific light source. The data can be loaded or dragged and dropped onto the selection. ColorAnt can also extract data (the white point) from a measurement file and display these values.
  • Emission (Measure): Opens the Measure Tool in Ambient Light Measurement mode. The ambient light can be measured directly from within the CIE Conversion tool using supported devices (e.g. X-Rite i1Pro and Konica-Minolta FD-7). For more information, see the Measure Tool help.

Observer: Can be changed from 2 degrees to 10 degrees.

Resulting file: Spectral data are converted to Lab during CIE conversion with the set illumination and the selected observer. The resulting measurement file contains only Lab values. You can then use this file to create profiles.
Note: Use the CIE Conversion as the last step due to the conversion of spectral data to Lab.

Important: The CIE Conversion can only be used with spectral measurement data from test charts, otherwise the tool is grayed out.

Procedure:

  1. Select a spectral measurement file of a test chart and open the CIE conversion.
  2. Under Illumination, select one of the predefined illuminants, or manually enter the measured illuminant as Kelvin value or XYZ value. You can also simply drag a measurement file (TXT and CxF3 file) of the measured light onto the value field. Alternatively, to select a spectral light measurement, select Emission (Open File) from the drop-down menu and select your measurement file in the subsequent dialog.

    Note: If you choose to enter your own illumination, it is recommended to work with one of the two emission options, since spectral data is used throughout.
    Multiple measurements of the same light source: If there are multiple measurements in a measurement file, it is best to use the Redundancy tool for averaging, to save the file and then use it as an Emission (Open File) in the CIE Conversion.
  3. Under Observer, select the desired observer angle, 2 or 10 degrees.
  4. Click Start and the spectral data are converted into Lab.