CIE Adopts TM-30 (sort of)

May 3, 2017 in Color, Light

The CIE has issued a statement titled “CIE 2017 Colour Fidelity Index for accurate scientific use” in which they partially adopt the Rf fidelity metric of TM-30.  Here are some of the details.

When the IES released TM-30-15 it seemed to be a wake up call for the CIE, who have understood the inaccuracies of CRI but haven’t been able to build the internal consensus to correct them.  Two CIE committees soon began  work, one on the issue of fidelity and one on other perception related issues.  The committee that worked on fidelity (TC 1-90) has decided to adopt TM-30 Rf with a few minor changes to the calculation.  They are calling this the CIE 2017 Color Fidelity Index, which will still be described as Rf, and are asking the IES to adopt the same changes to the calculation so that both Rfs are the same.

However, at this time there is no retirement date for CRI, even though they acknowledge that Rf is more accurate.  The logic is a bit twisted.  Since CRI is used for purposes other than the intended purpose, and since TM-30 doesn’t satisfy those purposes, we’re going to continue to mis-use CRI.  Meanwhile, “replacement of the CRI will be a matter of future study and discussion.”

I’ll probably have more to say once I read the entire report.  If you want to read the report yourself you can purchase it here.