Quote - > Quote -

Strictly alpha maps are not the same as transparency maps, alpha maps only modulate the overall transparency for all colors. A transparent map can modulate each RGB component.
Poser only use alpha maps.

My C4D materials have seperate settings for alpha and transparency. Other Modelers too.

But Lux seems to act like Poser: There is no alpha-channel we could use (I couldn't find something). So, indeed, your right. For Lux transparency == alpha.

LuxRender also separates between transparency and alpha.

Transparency is meant for materials like glass, driven by physical properties like reflection, transmission, IOR etc and not with a map.

Alpha is done in LuxRender using a mix material, where an alpha map can be applied to each layer.