In this video I am removing the noise from a tunnel animation in Blender. I could have rendered it at a high number of samples, but this would have taken almost a month and I do not have a render farm, so denoising in the compositor was my only option to avoid all of the noise. There are new Blender builds with a built in denoiser, but this denoiser node group has a lot more settings that you can change and the built in denoiser uses a similar blurring method.