Just thought I'd pass this on. I painted the inside of the Fotodiox Pro adapter with Krylon Ultra Flat Black paint.
Camouflage Paint made with Fusion for PlasticĀ® Technology - | Krylon
It's a big improvement. Flare from lights just outside the frame is slight or there's none at all. The reduced contrast/fogginess around the tops of trees on an overcast day is no longer there.