Here's a subtle difference between the Firefly and newer Superfly renderers. I'd never bothered to try the new one until now; it turns out to help in this peculiar situation.

I'm doing my usual trick of setting up a complicated displacement map with a model, so the 'real' Poser model can be simpler. This is meant to be grooves for a record. There is NO LIGHT in the scene; the gray values are set by controlling the ambient value of the material with the P variable. Higher parts = lighter gray.

The upper render is Firefly, the lower is Superfly. Firefly created a moire pattern, just like you see on a real record. But I didn't want a moire here; I just wanted a plain replica of the groovy model. Superfly handled it better.

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