This issue has been confusing to me for a while, according to the calcs below on Meyerfire Prep 2019, it looks that Lumens = cd, I doubt this is correct.
If I search the internet, there are should have a factor, which is the solid angle.
Cd = lumens/ sr
From Wikipedia I found that E is Illuminance which is in lumens/m^2 which is the incident flux on a surface, as in the problem. One lumen per square meter is a Lux.
Are the units on this correct?
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