Simple technique to reduce noise on Cycles
What is your preferred method to get rid of noise from renders in Cycles? The first choice for a lot of people is to increase the number of samples, which may result in several hours of render time. Another option is to add even stronger hardware, like high-end GPU models. As a downside, you have to make huge investments to get the latest boards.
What if you could get a significant decrease in noise levels by rendering the same image twice? The technique may seem strange but makes perfect sense after you make a few tests. Do you want to check the results the method? Take a close look at this project from artist SunBurn.
Despite the fact that all renders look amazing, you can read the descriptions of the project that his method to reduce noise in all images is to render each image twice, with a different seed. That will generate noise, but at different locations across the image. When you blend both images together, the final result will blur out most of the noise.
The process is incredibly simple and could be performed by anyone with the available time to spare on a second render. But, as a way to get less noise from Cycles it surely worth the try. You will end up with a cleaner image and will also save some money by not having to upgrade to the latest hardware, at least for a while.
If you are not sure about the process, just make a quick test before you choose to adopt the technique. Since it may add significant time to any render, you can even try to work with lower samples for your render.