Set 407 was supposed to be a two-night shoot. The hallway had other plans — a practical ceiling light with a green cast that fought every LED we put next to it.
We gelled the practicals rather than the lights. Cheaper, faster, and it kept the ambience feeling like the building instead of a set.
The final sequence was shot handheld at 1/50 with a 40mm. No stabiliser. Some of the best takes were the ones where the operator was slightly out of breath.
The lesson: protect the atmosphere first, fix the technicals around it.