Bedroom at night background

[bog]

that tree shadow looks really wrong to me. Wouldn't it be a lot bigger if the tree was outside?

[Andail]

Depends on the light source

If it's moonlight, any cast shadow regardless of distance would be of the same size as its object, since the light is virtually parallel. (It's the same with the sun, obviously; the shadow of an airplane is never bigger than the plane itself, regardless of its altitude; the sun beams hit the plane parallel and won't project the plane any differently on the ground).
If there's a lamp post right behind the tree, it would indeed be much bigger and furthermore much more diffuse.

I think the shadow needs more blur to it, as it looks like an exact projection right now.

Apart from that, the room is too equally lit, in my opinion. If the window is the only light source, why not make the corners and walls to the right a bit darker? Don't use gradients, just add more shadows the farther you get from the window. Remember that the reasons for shadows being blue is that the blue sky becomes the prime light source. It doesn't mean everything that isn't hit by any other light automatically becomes painted clear blue. You should probably add more black as you move away from the window.

[Ookki]

Ok so I tried a little different approach this time. I replaced the tree shadow with a two part window so the window makes the shadow. Also I made the room a lot more dark. Maybe I still should try it out with yellow light but it's kinda hard it to get the same feeling of night, it looks more like dawn when I tried it out last time.

Any suggestions how to make the change from light to complete darkness look more smooth?