I'm rendering a glass of beer and I'm finding that the default Arnold Quad Lights do not provide realistic reflections when compared to a plane with an emissive material. The internal reflections are drastically different (and improved) when geometry is used in place of a quad light. Attached are two screenshots of the different lighting methods. I'm wondering if this is just an inherent limitation when rendering glass or if there is some sort of work around since using emissive materials requires much longer render times. Any advice would be appreciated.
Quad light - light-v1.png
Plane with emissive material - geometry-v1.png
You may be better off using a mesh light instead, and making it visible.
You could also try disabling internal reflections.
Thanks for the answers. The mesh light has the same affect as the quad light but disabling internal reflections could be a solution when speed is more important than realism.
Attached is a render with internal reflections turned off. Not as realistic as an emissive plane but it's much faster. It's also better looking than using a light with internal reflections turned on.