This web app calculates Spot Color Tone Value (SCTV) directly from spectral reflectance data.
Measurements conditions are as follows:
StartWL - Start wavelength for measurements in nanometers.
Step - Measurement increment for example: StartWL = 360 and Step = 10, then measurements are done in 360, 370, 380...
Illuminant - Type of light source used for measurements.
SCO - Standard colorimetic observer, 2 = CIE 1931, 10 = CIE 1964.
First three fields are mandatory, substrat, spot color at 100% and at least on tone value. If needed additional tone values can be added with adjusted values. Spectral reflectance data is raw measurement from spectrophotometer, values should start from StartWL through rest of color spectrum.