Problem with alpha channel

I wonder why the alpha doesn’t take into account opaque objects behind transparent objects.
What I mean is that if, for example, I have a pair of reading glass on a table, the alpha channel will have the glasses in black even though the table top has no transparency.
Most of the time it’s pretty easy to correct the alpha channel in Photoshop but it can lead to mistakes (like having a composited background showing in unexpected places)

Hello,

Simply set the Material Refraction’s option “Affect channels” from “Color only” to “Color + Alpha” or “All Channels”.

Kind regards,
Peter

Thanks Peter