So here is something that I don't think I've come across before. When I render this scene full frame, the cliff on the right casts a shadow across the canal. But when I render a crop, the shadow disappears. This is with the standard renderer but I get the same result with pathtrace. Both renders use the same gi cache file.
The thing is, I want this shadow in the final high-resolution render. I was planning to spread it out over several nights by rendering tiles. But the shadow disappears from the tiles.
Stumped here. Anyone have any ideas?