I am currently writing a paper on renderers. I have made a scene and rendered it using Arnold, Renderman, Cycles and LuxCore. What surprised me is that even though they all have the same settings (aperture size, focal distance etc.), the depth of field in the different images appear quite different from each other. The blur varies in size and appearance in all images. So my question is, how can this be? How is Depth of Field calculated in Arnold?
Any help on this matter is much appreciated!