Lens effect - Depth of field
Before we jump into this tutorial first we will talk about a property of camera called 'Depth of field'.Camera has many property Film gate, FOV , Focal length etc. but we here talk about Depth of field. This property give us information about another object is how much far from Target object by blurring the scene.
Simply we also use Depth of field direct from Target camera parameter but it take much time for rendering because each passing image is one type of render and for good quality of depth of field .We must increase the passes value. guess that i increase the passes value to 12 it means final render image takes 12 time render time.( Increase the passes number, increase the rendering time).
3ds max give us second type of depth of field in MENUBAR>RENDERING> >EFFECT.click on effect tab. in this click on ADD and select DEPTH OF FIELD from list. In depth of field parameters select PICK CAM and select camera from view. (Here remember that select camera not camera target) Select another option PICK NODE in this parameter and pick camera target from view. I think There is no need to change other parameter Focal range, focal limit etc.This effect uses less rendering time instead of Direct depth of field from Camera parameter.