Explaining the effects work on Solo, Cinefex issue 160 describes two ways the team used screens as carriers of ersatz reality. The first makes use of a tablet to simulate a window:
The coaxium containers have windows through which the liquid material can be seen sloshing around. Rob Bredow shot footage of ferrofluid which the props team puppeteered using magnets; ILM stitched the plates into seamless loops. BLIND fittet a Microsoft Surface Pro tablet inside a prop container, on which the coaxium footage was displayed.
The second way recalls the way Gravity created Sandra Bullock’s surroundings and constitutes a sort of advanced rear projection, with screens showing the space around the “Millenium Falcon” cockpit set:
Immersive environment specialist Lux Machina surrounded the cockpit with a 180-degree rear projection screen illuminated by multiple 4K projectors in portrait mode. To feed the projectors, ILM finaled visual effects backgrounds prior to principle photography. “We generated wraparound content just as if we were working on a simulator film, with beats that either looped or were much longer than if you were just doing the two or three seconds that end up in a shot.” The rear projection approach – also used for scenes inside Dryden’s yacht – enabled [DP] Bradford Young to capture cockpit shots in camera, backgrounds and all, using the screen as his primary lighting tool.