Excessive noise

Subtle high-frequency noise is normal for Corona and other path-tracing renderers, especially at the beginning of the rendering process. But strong noise that won't go away after many passes, or after long rendering time, may suggest that the rendering engine encountered some problems in your scene setup.

If you are certain that the noise problem is caused by a bug, please report it to us.

For possible solutions on excessive noise, see: How to get rid of excessive noise?