Plastic base of analog film strips — cellulose nitrate or acetate with light-sensitive emulsion. The physical medium of all cinema before digital.
On set, celluloid was the only material that mattered for decades. You held a light-sensitive plastic strip in your hand—equipped with silver halide crystals in a gelatin layer—and that's where it all began. Cellulose nitrate in the early decades, then cellulose acetate as a safer variant: both substances enabled what we called cinematography. The physical base determined your image quality, your color reproduction, your grain, your light sensitivity. You chose your film stock like you choose a camera today—based on contrast, speed (ISO), color character. Kodak, Fuji, AGFA—each stock had its own sound.
In practice, celluloid imposed constraints that no longer apply today. You couldn't shoot for an arbitrary length of time; the roll would eventually fill up. You had to know what you were filming before you filmed it—no downstream color grading on a monitor. Chemical development was a separate process, time-consuming, expensive. A discarded take was truly gone. At the same time, this limitation created a captivating aesthetic: the natural grain, the subtle color casts, the roll characteristics that gave the image character. Some would say: a character that sensors still try to emulate today.
On set, celluloid also meant weight and logistics. You needed cool boxes for storage because changes in temperature affected the emulsion. You changed magazines under a black flag. Halation was your constant adversary—every scratch on the stock showed up as a glowing line in the image. The film reel was a precious object, not just a file metaphor as it is today.
Digitalization hasn't made celluloid disappear—it's still shot occasionally, archive material is scanned, its aesthetic remains present. But the routine is over. Anyone working with film today does so consciously, out of love for the material, not out of necessity. This has strangely mythologized the status of celluloid: what was once a technical fundamental reality has now become a creative decision.