Orthosphere view mode
Use the button in the camera pane, or ctrl + j to enter and exit the orthosphere view mode.
The orthosphere view mode blends the two hemispheres of the orthographic projection in panorama mode on top of each other to simulate a full celestial sphere. There are two profiles:
Orthosphere – the base mode, in which both hemispheres are blended on top of each other.
Orthosphere cross-eye – a stereoscopic (3D) cross-eye mode which lays the images for each eye side-by-side.
ctrl + shift + j – Cycle between the different profiles.