Weird blotchy shadows in blender cycles (denoising) I have an interior scene with a window opening, a portal light in the window and an area light acting as sun light. I want to achieve this dramatic cinematic feeling without interior spot lights apart from the kitchen counter light. I know its hard to properly denoise these kind of scenes and im very new to blender (i have a modo and vray background)... I keep getting this blotchy shadows and i cant get rid of them nor de noise, i used to have a hdri to iluminate my scene but i changed it to an area light with no improvement, i started with 1024 samples and now im on 9000+ samples with no aparent improvement... render time is crazy high and the result is the same. Im trying to get Optix denoising to work on my gtx 1070 on a custom build i found online with no luck
This is how to use Intel Optix Denoise node in compositor.
Basically instead of using the Blender denoiser, using this node allows you to denoise a scene using low samples, and without creating splotchy/dark areas.
Downsides? This node may cause blurring in some areas, when used with very low samples.
This image is with regular denoising, rendered at 4 samples (to show effect):

This is the same scene, but using the denoise node in the compositor to denoise:
This is the original image without any denoising:

As you can see, it has a major effect on render times, and denoises well, but it can be blurry on very low quality renders.
You can enable this node by going to the compositor, and clicking &quot;use nodes&quot;. Then add the denoise node between the image node and the output node. (You can press Shft+A to pull up a search menu for the node).
A simple connection between the image points should do the trick:

If that is too smooth, you can try connecting the image node to both the image and albedo points on the denoise node:
The node runs on your CPU, so there should be no reason why you can't get it to work.
For more info about connecting the denoise node, see this post:
How to properly connect the Denoise node in Compositor?