Hi - me again.
I have tried playing with more lighting settings in P3Dv4 and discovered that the problem occurs when you set simobjects / buildings / vegetation / vehicle (aircraft) to "receive" shadows. Which ever object is set to receive shadows then lights up (or doesn't) depending on the viewing angle and even the zoom setting in the evening (i.e. at dusk - and perhaps dawn as well but I have not tried it at dawn yet). In other words, for some viewing angles, the objects "incorrectly" do not receive shadows and then appear to be lit up by the ambient sun light !
So - apologies for "discovering" this while at CYVR and thinking it was an airport problem.
Please kindly indicate that this issues is resolved.
Kind regards,