Motivated vs. Unmotivated Lighting: When to Break the Rules?

Hey everyone,

I'm Antoine, a camera op usually running an ALEXA Mini or sometimes a V-RAPTOR XL on narratives and commercials. I was rewatching Sicario recently, and the discussions about Roger Deakins’ masterful 'motivated lighting' have me thinking. It's truly incredible how it grounds the film in realism.

But this got me wondering: in your experience, when does this 'textbook' motivated approach not serve the story? I've been on projects where sticking strictly to motivated sources (say, just relying on a small practical and a single Forza 720B for a night interior) sometimes felt too dark or muddy, obscuring character reactions crucial to the scene. Later, in the edit, we'd wish for more clarity.

So, when have you found yourselves needing to 'cheat' with unmotivated light for narrative clarity, emotional impact, or even just a more pleasing aesthetic, despite the 'rules'? What are your go-to tactics for integrating that 'unmotivated' hit without totally breaking the illusion?

Cheers, Antoine