How the CIE Spectral Calculator Works

The CIE Spectral Calculator is a tool for studying, comparing and visualizing various spectral CIE functions.

Simply use the checkboxes to enable/disable any of the functions.

Toward the bottom is a general Standard D Illuminant calculator that computes and displays the spectrum from any correlated color temperature you enter (must be in the range of 4000 to 25000 K). Below that you will find a blackbody radiator which will compute and display the spectrum of a blackbody radiator of the temperature you choose. On both of these, you must click on the graph to cause an update using the new temperatures you have just entered.

All graphs are computed at 5 nm resolution.

Some observations:

• Standard Illuminant A is, by definition, the same as a blackbody radiator of temperature 2856 K.
• Standard Illuminant B is generally similar to D50 and a 5000 K blackbody radiator (actually closer to 4871 K).
• Standard Illuminant C is generally similar to D65 and a 6500 K blackbody radiator (actually closer to 6769 K).