Does increasing the margins for reflection planes in Lumion increase render time and is it better than adding more planes?

Background:

Reflection Planes can be added via the Reflection Effect to create mirror based highly accurate reflections.  They require an additional render of the complete Scene.  See this article:

• Knowledge Base:  How do Planar Reflections work?

Reflection Plane Margins:

Increasing the value of the Margins slider does not increase render times.  It simply expands which (parallel) surfaces are included to receive this type of reflection for the Scenes content along the chosen plane.

With no Margin only the single window surface matches the plane.

Increasing the Margin might include surfaces in the same plane. Adjust the material for Reflectivity and Gloss if needed.

A high Margin that now also includes the other window that was set back in the model.

 
As a consequence, the render times are considerably lower in comparison to adding additional Reflection Planes.

However, depending on your needs, using another Plane will improve the correctness of which surfaces have this type of reflection.  For example in the above, the window frames are also included to receive the final rendered Planar Reflection.

Increasing the Margin too much can have this impact:

1.6:  ...The further away a parallel surface is from the Reflection Plane, the less accurate the reflections will be.

• Knowledge Base:  How do Planar Reflections work?

See Also:

• Knowledge Base:  How do Projected Reflections work?
• Knowledge Base:  How do SpeedRay Reflections work?