Everything in front of the camera — production design, costume, movement, light. Distinction: what exists physically vs. what's created through editing/VFX.
The core lies in a simple but fundamental distinction: what you build up as physical reality in front of the camera—sets, actors, real light, tangible props—that is pre-filmic. Everything that arises afterward, in editing, through compositing, or digital color, is not. This demarcation directly affects your work as a cinematographer because it determines where you invest.
On set, this means: You can shape a character pre-filmically—through their clothing, their gait, the way they enter a space. This is immediately visible; you control it directly. A shaky glance that editing later amplifies? That's not your responsibility as DoP; that's post-production material. But if your lighting builds the depth of a scene, clarifying the hierarchy of characters through brightness ratios—that is pre-filmically effective and your creative power. Your lighting exists in reality before the first second is filmed, as planning and setup.
This becomes practically relevant during preparation: If you discuss with the production designer how the scenography works, you are both operating in the pre-filmic space. You can experiment, change, and readjust. If the director later adds digital effects in editing or fundamentally shifts the colors—that's not a criticism of your pre-filmic work; it's a different layer. The distinction also protects you: You know where your control ends and where post-production begins.
The term originates from film theory but has tangible practical consequences. It explains why a masterfully lit set remains legible even under poor color grading—the pre-filmic structure is solid. And it explains why pure VFX shots without real spatial depth, without pre-filmic dimensionality, often feel hollow, no matter how technically perfect they are. You need the physical reality in front of the lens as a foundation. Everything else builds upon it but cannot replace it.