sneak

[radiance]

in order to make the node system uniform and programmable,
a node can only have one output (otherwise you would not be able to swap nodes in the node inspector only).

The output of a texture node is always a texture, be it a float value one (greyscale) or RGB.
If we would combine the A channel into it it would remove a lot of flexibility...

alpha image loads an image and extracts the A channel as a float texture (eg grayscale)

Radiance

[matej]

in order to make the node system uniform and programmable,
a node can only have one output (otherwise you would not be able to swap nodes in the node inspector only).

I see. Thanks for the clarification.