Sun Nov 19, 2017 12:59 pm
Fusion free can work internally in more then UHD, mostly output is restricted to UHD.
When you change the preferences, did you change it for the global or the comp itself? What did you put in the viewer to see the "canvas"?
The new resolution is only set for newly created nodes which use the "use frame format setting" enabled. If you have disabled this by default all nodes will be created with the fixed settings from you defaults.
If you create a new background after you have changed the frame format in the preferences and put it on a viewer you should see that it is in the new size.
Also remember that fusion will take the frame size from the background input of the chain. If you have a 1024px image an put an UHD image over it your resulting image will be 1024px