thatks for your reply. The final render below is with 700 rays. But there is still some lines of FG shadows below car. Light is setting good I thing. Photons is computed relative fast. Bud FG is slower and main rendering is the most slover. Why Mental ray find so large max radius if my scene is small....? And model has something around 500000 polys [Modeled by cps tool] and I saw that in the begining of rendering taking a lot time subdividing objects[all object has maximal 2 subdivides] it is normal? Why I render picture 640x480 so long...Thanks