Glass / Postwork issue

[bpzen]

Hey there,

Im having an issue I have not had in the past. Rendering a room with windows, I want to make the outside look dark / night time. The glass mat is set to .1 opacity and renders fine - alpha channel is on.

When I bring into photo shop I place a black background layer behind teh render, teh color of teh black background look s grey through the windows... I know ive done this before and had the black color I am looking for show. Any ideas on what im missing?

its like teh rendered windows are stopping some color from showing...

thanks

[face_off]

Glass should be a specular material with opacity set to 1. Use the correct IOR (index) which is 1.3 or 1.4? And tick the "Affect Alpha" checkbox in the Specular material.

Paul