How to convert Melanopic illuminance to EMl or m-EDI

radiance-general
1

Hello everyone,

Based on my understanding, the output unit of rtrace with the -pM option and rcomb with the -c M option is melanopic illuminance (mev) in lux. I am trying to understand how this value is calculated in these commands. I traced the process back to scolor2melanopic in spec_rgb.c, but I am still not sure how to convert this result to EML or m-EDI with Radiance.

Is there any command in Radiance to perform this conversion?

Thank you,
Soushiyant

2

The short answer is to divide melanopic illuminance, which is defined in terms of an equal-energy illuminant by 1.1 to get mEDI, which is based on D65. This is the ratio of luminous efficacy between EE and D65.

Best,
-Greg

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