this is what i mean,the bride in a super bright background,
by the way tanx Chris im reading that article you send.but i have a big problem with luma and chroma.
there should be a way to isolate back Scene and for Scene.
I don't even think the rotobrush will help you here. The veil on her head and sky are blown out. Not sure if you tried color correcting to see if you could get any additional info back, but I think it is probably too over exposed. You could try to manually rotoscope, but the computer can't differentiate the veil and sky and I'd be surprised if you could while going frame by frame.
There's no way to isolate the foreground and background when both are essentially pure white.