Reply To: Not understand about lum sentence
@adrian2301 I do not know how Unity does this, but actually, Luminance is perceived brightness and therer are several definitions/formulae to calculate Luminance from RGB (and there are also several RGB models, so t’s a big mess…)
Blender, for instance uses two different Luminances: Shader Editor: RGB to BW Node, which is the same as the Y in the YUVA in the Compositor, but then there is also the Y in the YCbCrA, which is different as you can see here:
I think you are confusing Luminance with Luminosity, Adrian (which is totally understandable, this is sooo confusing and most people get it wrong as soon as they start talking about diiigtal color, including me!)