I was duplicating Celshader's tutorial on SPLINE INSTANCING, and rendering it out over the weekend 'cuz I'm out most of the day.

There're volumetric lights, motion blur, etc, but at a certain point in the animation the noise in the image gets very noticeable. Here's the Scene:

I'm particularly looking at Frame 222. I started ratcheting up the Lighting samples, then the shader samples, THEN the volumetric quality, but nothing really seemed to affect the noise all that much.

My grasp of the various sample settings remains tenuous, since they are interactive amongst each other and sometimes non-intuitive: can anyone shed some light on this?