Path tracing, only emission lights. render time 3 minutes 57 seconds.

Path tracing with MIS of the scene with absorption glass. Render time 4 minutes 32 seconds. min samples 64, max samples 640, threshold 0.000001, path trace max bounces 10000, Russian roulette after bounce 3.

Path tracing with MIS of the scene with light, emission, and object motion blur. Render time 3 minutes 29 seconds. min samples 64, max samples 640, threshold 0.000001, path trace max bounces 10000, Russian roulette after bounce 3.

Path tracing with multiple importance sampling and caustics. render time 11 minutes. min samples 64, max samples 640, threshold 0.000001, path trace max bounces 10000, Russian roulette after bounce 16. Even after increasing the Russian roulette termination bounce, only a some color difference is seen.

Path tracing with multiple importance sampling and caustics. render time 5 minutes. min samples 64, max samples 640, threshold 0.000001, path trace max bounces 10000, Russian roulette after bounce 3.

Multiple Importance Sampling

Only Light Sampling

Only BSDF Sampling

Path tracing with only the emission wall, no lights.