One way to identify where the fireflies are coming from is to render the scene using AOVs.
- Open the Render Setup window and select the AOV Settings tab. Add an output file such as EXR.
- Select direct_specular, indirect_specular and reflection. These new AOVs should appear under Active AOVs.
- Render the scene and open the AOVs or render them in the Render View window (select the AOV from the Render View AOV dropdown list above the AOV Browser.
Choose the AOVs you wish to identify
Two Standard shaders connected to Rayswitch shader