I've been reading through past posts to see if someone else reported a problem like this before. No luck. I saw a post talking about lines related to displacement maps. Nope, turned off displacement. Saw a post talking about lines related to use of spotlights. Nope, all Universals.

Anybody got any suggestions?

Firefly render, raytracing, dynamic hair, Nerd3D's background prop, backfacing polys removed, displacement turned off, 11 Universals arranged in equidistant manner around subject

P4 2.2GHz w/1G RAM.

Are you using depth of field? Usually, you get this effect when using depth of field with a too low number of pixel samples. While it's a little hard to figure out what's going wrong without knowing the scene, lety me try: First - does this happen also when you turn off shadows? Does this happen when you use Shadow Maps? How many lights are in the scene? If this does not happen without shadows, try increasing the min bias value for the lights. Do you have texture filtering turned on? Also, I do not own the background prop - is it made from double-sided polygons? Did you turn off "cast shadows" in the parms for the background prop? Also make sure you're running SR-3. PS: Great looking hair!

I believe this is called self-shadowing, and can be controlled by adjusting the shadow min bias on the light. Set it to a lower value and try that. I find that a setting of 0.3 to 0.5 is good for most things. It can also be caused by double-sided polygons and polygons in the same plane. To correct for that go to the materials for that object drag a connection form the texture map to the displacement node and set the displacement value to 0.001. Be sure to turn displacement back on in the render options. One of those two should fix the problem.

I don't know why this happens but you could make a new 'high res square' (or Nerd backdrop prop), texture it position it and delete the old banding high res square (or Nerd backdrop prop). This worked for me.