Link: https://lightsandlamps.com/products/3-light-aged-brass-and-opal-ceiling-wall 

Modeling for smoothing: the Turbosmooth modifier is present on the panel - it is open, adjust the degree of smoothing at your discretion.

Renders are made in Corona Render 9. Corona Legacy Mtl.
"For Corona Render: it is recommended to install version not lower than 1.5, since the glossiness of materials is configured taking into account PBR."