MAX RAY INTENSITY: Avoids fireflies and noise when there are bright lights and reflections in the scene.
TWO-PIXEL AREA FILTER: Gives a soft, more filmic, edge to the image.
LOW AA MAX SUBDIVS: 6 is probably the lowest you can go. All the work is done by the DMC sampler.
COLOR and DMC THRESHOLDS: If you want fast, don’t use the DMC sampler threshold here and raise your color threshold until you see noise appear. 0.02 worked well here but you may have to go lower in some situations. My DMC noise threshold is set a bit lower at 0.01, but both are actually quite high compared to my stills settings.
LWF AND CLAMPING: I hate to clamp as it drastically limits what you can do in post, but in this situation, it was a must as it gave a nice speed boost and a cleaner image, albeit one devoid of any dynamic range. This means I had to render a separate pass with just the fluorescent lights, which I used for glow and flares.
GI & LC: The IM is set at low quality, but the Subdivs and Interpolation samples are set at 50 and 50 to eliminate all blotches in the corners. Such a smooth IM is nice and clean for scenes that rely a lot on direct lighting but wouldn’t work as well in scenes were the GI does more of the heavy illumination lifting. The LC is left pretty much at default but I use it for glossy rays for a small speed boost on reflections. Retrace is on, which actually increases render times slightly but it’s a must to avoid light leaks.
MISC SETTINGS: I use a small bucket size because I’m just impatient, and don’t forget to tick Embree if you use Intel processors.
That’s pretty much it. Ask if anything’s not clear and let me know what you make of these.