Picture and sound recorded on one medium — archaic approach, sync-free but inflexible. Double System is now the only professional standard.
In Single System, image and sound run on the same medium—classically, magnetic film with parallel tracks, or modern digital formats that store both signals. The key advantage is synchronization: you don't need a clapperboard, clapper codes, or a separate sound recorder. When playing back, image and sound are automatically aligned. This sounds tempting, and indeed, Single System historically shaped documentary filmmakers and TV crews—anyone who needed to be mobile opted for the Single System camera.
However, in practice, it quickly becomes clear why this method is out of fashion today. Errors on the medium immediately destroy both channels. Scratches, wear, magnetic adhesion—a damaged spot costs image and sound simultaneously. With Double System (image and sound separate), you can still salvage what can be salvaged. Editing also becomes a nightmare: if you want to post-process the sound, you have to duplicate the picture edit or go through complex conversions. Modern workflows demand sound and image completely decoupled—only then can professional post-production, color grading, and sound design function.
Today, Single System still appears in fully digital systems where the camera and audio interface truly form a unit—for example, with certain mobile or broadcast cameras. But even here: at the moment of export, they are immediately separated again. Storage in the same container is merely practical for transport and initial checks. True Single System philosophy, where you never separate the tracks, no longer exists in professional cinema.
Anyone still working with magnetic Single System copies knows the ritual: digitize the material, split it immediately, sound to the audio layer, image to video. The nostalgia kick is there—but productive? No. Single System was a necessity of analog technology. Today, it's a relic that you respect, but do not emulate.