Compositing reflection pass in Photoshop / AE


I’m setting up a layered Photoshop file ready for projection as a 2.5D DMP in After Effects.

The shot is looking through a room’s window to a landscape beyond, so I’ll have some solid foreground elements, along with the window having a degree of translucency.

I want to add in a reflection of the room’s contents on to the window glass, but I’m struggling to get it to look right. I’ve done a render with the glass set to a mirror, which I’ve then applied to the glass using Linear Dodge blending mode - I’d read this is the correct way to add in a reflection pass.

It doesn’t seem to look right - I’ve dropped the opacity to about 30%, but the contents looks really blown out / burnt in the light and dark areas.

Am I doing it right? And if so, will AE give me the same results when I start animating?