I'm gaffing a graduation project at The Norwegian Film School these two weeks. The entire film takes place in one apartment, with two characters, and the light plays a central role in telling the story. We're trying to create a moody but realistic daylight, accompanied by sunlight moving across the sky during the day. The soft sky is created by dressing the studio walls and ceiling with 12x12 bounce, and blasting T12's or 4K HMI's into it depending on what colour sky we want (we're also gelling about four different colours of sky, including night sky). For the moving sun, we've got 2K's hanging on a truss, one for each window (a lot of careful flagging), with a total of five different gel combos to emulate the rising sun, which we create by elevating the truss and sliding the lamps across. We also created a time lapse rig where the lamps are mounted on stands and moved by two dolly's joined together, while my trusty lighting crew pan'ed the stands to fake time passing.
Look out for the film, hitting festivals this summer! No official title yet, but it's one of six graduate projects from Norway this year.