Photons subdivs- this value is used by V-Ray when calculating the Global Photon Map. Lower values mean more noisy results, but will render faster. Higher values produce smoother results but take more time.
Diffuse multiplier - a multiplier for the diffuse photons
Caustics subdivs - this value is used by V-Ray when calculating Caustics. Lower values mean more noisy results, but will render faster. Higher values produce smoother results but take more time.
Caustics multiplier -this value is a multiplier for the generated caustics by the selected light. Note that this multiplier is cumulative - it does not override the multiplier in the Caustics render roll-out section.
