Direct Lighting

Setting	Description
Direct Lighting	Enable direct light contributions from light primitives
Enable Shadows	Enable shadows from light primitives (global setting)
Enable Sampled Direct Lighting	Enable a direct lighting mode that scales better to handle many lights. This mode is recommended to deal with scenes with more than about 10 lights.
Auto-enable Sampled Lighting Above Light Count Threshold	When set, the 'Sampled Direct Lighting' mode is automatically enabled when a scene has more than the number of lights set in the 'Auto-enable Sampled Lighting: Light Count Threshold' setting
Auto-enable Sampled Lighting: Light Count Threshold	The threshold number of lights used by the 'Auto-enable Sampled Lighting Above Light Count Threshold' setting

Setting	Description
Shadow Samples per Pixel	Higher values increase the quality of Direct Light Shadows at the cost of some performance
Lower Resolution Shadows Denoiser	Enable for better performance by reducing the resolution of the per-light shadows denoiser
Dome Lighting	Enable dome light contributions to diffuse BSDFs
Dome Light Samples per Pixel	Higher values result in more accurate dome light sampling
Dome Lighting in Reflections	Enable dome light contributions to diffuse BSDFs in reflections