Blender Cycles: Noiseless interiors with 250 samples
For every project related to interior visualization in Cycles, you have an enemy that will haunt you along the process, which is render noise. What is that? If you never had the opportunity to render anything in Cycles, the noise will appear as a kind of pixelation in the image.
To get rid of that effect you have to set more samples in render settings and leave the image processing for longer periods of time.
Before Blender 2.79 that was the only option to reduce noise. However, starting with version 2.79 we now have the incredible denoising option to remove render noise, using just a simple checkbox.
But, that comes with a price. A small blur in your renders, and for those artists that go too far with denoising settings the final render may become unusable.
Is there a limit to the Denoising? What about 250 samples?
I was looking at a project in the BlenderArtists forums from an Italian artist called gasteropode, and became amazed at the results. According to the artist his scene uses only 250 samples.
That is just one of his renders. Visit the link to the forum, and you will see the full set for that interior.
According to the artist each image took about one hour to render, and uses only 250 samples with the denoising option. He also describes his technique to get such clean renders. All renders using CPU mode only, which would eventually be much faster in GPU mode.
He doesn't use any Sun Lamp or Environment maps. Only a white background and two area lamps.
Despite being a simple setup, the final result for both lights and render is excellent. If you are experiencing problems to get rid of noise in interior render using Cycles, that could give you some ideas.