Quality-based sampling creates a very high amount of sampling steps

Solution

To get more reliable estimates we recommend to always use “Clamping” along with “Quality-based sampling” to reduce the number of so called fireflies, which are often produced when rendering rough surfaces, refractive materials, caustics and so on. “Clamping” will cut off such high energetic rays at a given threshold to allow a more reliable estimation of how many samples would be required to fully converge the image.