Background & Alpha channel

[40th]

When I use an image for background and save the render output to png, the BG is still visible in the glass (when looking through it).
The glass is 100% transparent and single face (no thickness)

Question: Is it possible to get glass 100% transparent, without the BG in alpha?

Here's what I mean:

[camionero]

Re: Background & Alpha channel

is the reflection on the glass what you are looking at and it will be saved beouse it is on the glass surface

[40th]

Re: Background & Alpha channel

Hi Camionero,
I'm not sure that I understand your question. But what I want is that the transparent glass will be transparent also in the alpha channel.