Particle system problem with V-Ray

I have some problems with particle rendering in V-Ray.

Why are the red marked areas black? At the left and the right side are two spot lamps so there must be enough light to lit.

I did not use children and i set the gravity to 0, but that shouldn’t be the problem.

I attached the settings and the picture if you need more settings or information just ask.

Attachments



No idea? I tried other camera perspecitive but doesn’t help…