high render samples still give me a grainy result

Hello all.

I am working on my first environment scene, and i have a little problem with the rendering.
I did a test render last night night to check how the environment looks, but even when i put the resolution at 4K and the sampling on 20.000 it still looks grainy.
I think it has something to do with the lighting within the scene.

The lights in the scene are:

  • a spotlight that casts light trough the window.
  • 2 lamps that have an emission object inside.

Does anyone know what i could do to solve this problem? i do want to keep the scene abit dark, so adding more light is something i’d rather not do.

This scene is still a work in progress.

Thanks in advance.

This is not a scene Cycles is particularly competent for…
An unoptimized pathtracer like Cycles basically fires rays from the camera and lets them bounce until they hit a light source. So, large room + small, hidden light sources = chance for a ray to hit a light source is extremely small = image takes forever to converge…

That doesn’t mean that there is no room for improvement… Any chance you could give us a simplified version of your scene to play with?