Operating system: Windows 10 x64
Broken: version: 2.82 (sub 6), branch: master, commit date: 2019-12-17 23:52, hash: e0cd5b980fc5, type: Release
As seen in T53517 comment :
Lamps are in Watts, [...]. Mesh lights are in Watts/m^2 [...]
Rendering the following two emissive items should give the same lighting :
- rectangle area light, 1m x 1m, power 1W
- plane mesh, 1m x 1m, Emission shader, strength = 1.0
This is not the case, area light power must be multiplied by 4 to get the same result.
Exact steps for others to reproduce the error
With the attached blend file,
- enable 'Rendered' viewport shading
- the 'Emissive plane' brings more light to the 'Ground' that the 'Area light'
- change the 'Area light' power to 4W