Visual effect artists create special effects, animation and fix up details for feature films/commercials etc. Compositing is another important job of the VFX artist at times, this is quite similar to digital matte painters who create realistic images for green screen backdrops.
Marc Simonetti produces top-quality artwork which has great visual appeal, colour harmony, light and composition. (See Simonetti’s work here)
Raphael Lacoste is another VFX artist who has worked on many major projects, the most interesting to me is that he was the art director for the first Assassins Creed game and as you can see below has produced very high quality artwork.
Below can be seen his concept art workflow.
(See Lacoste’s work here)