ARCameraBackground and transparency

Hi,

I looking for a solution to set everything transparent... but not really transparent. I want my 3D objects to render like opaque objects, but I want to see the real camera behind.

My scene is rendered to a RenderTexture already, so I tried to use CanvasGroup to set alpha to 0.5 but it gave me weird results (like an echo in the image). The only current solution i have is making every object transparent but it doesn't give the desired result (I don't want to see other objects behind my transparent objects if that makes sens).

Thanks in advance, V.