Increase brightness of HDR to light the scene, but keeping the background at a lower exposure I have a scene in which I am using an HDRI texture as a light source.  However, I am also trying to use it as a background, but when I turn up the strength of the sky it just turns white.  I am looking for a way to render the sky again(at a lower exposure) and then composite the sky under the rendered object.
Use two nodes for the background, one to light the scene at the intensity you want and one with the normal exposure that is only seen by the camera:
Control the mix using a light path using Is Camera Ray.