If there is one thing that can truly control the balance of speed versus quality in Vray it is image sampling. Image sampling is basically part of anti-aliasing. This tab can take your renderings from 20 second quick tests to 30 minute high quality renders without having to adjust any other aspect of the rendering. They control anything from fine detailed textures, to glossy reflections and refraction, to aspects like depth-of-field and motion blur, all at once. This tutorial helps to make sense of each one and simplify the process. Control the quality of the rendering in the most efficient way.