Motionblur Issue

[Ron Martin]

I experimented a bit with long exposure times for fireworks stills. I setup a scene with 4 seconds exposure and 100 frames motionblur. If i use visible animated light sources, the different lightpositions from my 100 frames animation are calculated and i get the effect of a tube shaped light. I also get the visible streak from the motionblur. If i use animated objects with a VRayLightMtl instead, the lighting is just calculated from the position of the actual frame 0 which i render. I get the tube shaped appearance of the motion blurred visible light object, but the lighting is calculated just from its position at frame 0!