Minimap screenshots

[Door]

In a lot of the map threads I've seen (such as Rhye's 18 civ Earth map) there are fairly large screenshots of the whole map without any clouds or fog of war. Does anyone know how these were taken? Is there a way to zoom out further in the worldbuilder to show the whole map? I thought they might be composite images but I'm not sure. Some of them look like minimap images, but have a lot more detail than my minimap. I'm sure I've missed something obvious and I tried searching but I'm still none the wiser. If anyone can tell me that would be great