Motion blur scene MUCH darker

[davision]

Is it normal for motion blur to darken the image? I have two headlights hitting the road in a night scene and their effect dims substantially when I enable motion blur.

[dimo]

There's a problem with lights and motionblur. The lights are static during the blur phase. As long as the lights are static in the scene this is no problem. But if the lights are moving you will get problems.
You should increase the area affected by the lights. For example with bigger falloff etc.

Best Regards,

Dieter

[vlado]

Since the headlights are smeared across a larger part of the image, it is natural that they should appear dimmer. Sometimes, unwanted darkening happens also if you have the "Clamp output" option ON in the color mapping parameters.

Best regards,
Vlado

[dimo]

I'm not sure. I made a small testscene. Take a sphere and link a light and the camera to it. Then move it fast.
If both the camera and the light is linked to the moving object. There should not be a difference if you turn motion blur on? But it gets much darker.

Best Regards,

Dieter

[vlado]

That would be because lights do not take moiton blur in account... so the sphere and camera will be moving, but the light will not.

Best regards,
Vlado

[dimo]

Is this considered as a bug?

Dieter

[vlado]

More like "not implemented" stuff. Further on, it can be implemented only for the VRayLight.

Best regards,
Vlado