Bump mapping in Corona doesn't resolve micro details consistently well. It usually depends largely on the distance to the object and the blurring of the map. Especially useful for metals, an improvement in the bump mapping to achieve realistic brushed effects, for example, would be great and consistent with Corona's policy of working towards the most realistic rendering engine.
Hi, in newer versions of Corona (I think since 10 or 11) we have this new roughness modulation mode for normals: https://support.chaos.com/hc/en-us/articles/19161682524305-New-Bump-Normal-Filtering-in-Corona
One of the goals of this is to make bump/normal mapping appear consistent independently from the viewing distance.
If you have some example scenes where bump/normals are not rendering as expected, could you please share them with us at https://support.chaos.com/hc/en-us/requests/new ?
Thanks in advance!