Whenever I turn on “ray variance anti aliasing” I get these artifacts where certain buckets come out darker. Predominantly in shadows. This does not happen if I turn “ray variance aa” off. Is this something that is apprentice specific? I get it on any machine I try it on. Is this something anyone else has seen?

The only time I've seen these type of artefacts is when using the Preview render. Can you confirm that you are using buckets and not Preview? It's on the Render View pane, small icon with coloured boxes. Another way to tell is that Preview ON = Renders progressively, Preview OFF = Renders as buckets.

Any Houdini version, apprentice or not, shouldn't give this kind of artifacts.

If you are rendering on the render view, do you have preview mode turned on?

If you aren't using it, maybe try post here the render settings

Edit: Rob has been faster

Thanx guys!

It is apparently the aforementioned pixlycolored icon for progressive mode in the render view that cause it. Odd error. I will log that as a bug.