Double exposure — one image exposed over another, achieved by advancing film multiple times or digital compositing. Classic for flashbacks and supernatural effect.
Double Exposure — two or more images overlap on the same film material or in digital compositing. This creates a translucent, often ghostly effect on set or in editing, visualizing thoughts, memories, or supernatural presence. Classically, this was achieved on 35mm or 16mm by rewinding the film after the first exposure and exposing it again — a technique that carried sources of error but had an authentic character precisely because of it. Today, this works digitally through simple alpha channel overlay, but often loses that visual rawness.
The practical challenge in the analog process lay in exposure calculation: if both takes were exposed normally, the image would overexpose. Each take had to be underexposed — often by half or a full stop — to avoid overexposure. This resulted in a characteristic, slightly pale ghost image in the darkroom look. Modern cameras with multi-layer sensors now allow for better control, but the effect then appears sterile if a fade effect or grain isn't consciously added.
In editing, one works with crossfades or keyframes to control the visibility of the second image. A classic flashback: the actor sits in the foreground, behind them the memory scene materializes with 40–60% opacity — washed out, unclear, spatially unbounded. The signal to the audience is unmistakable: this is not the present, but memory or dream. On the other hand, overly transparent ghost images today appear careless. Professionals prefer to work with blur, slight color shifts, or vignettes to give the effect depth.
Ghost images should be distinguished from split screens (spatial separation) or from pure transitions like dissolves. A ghost image *superimposes* spatially — both images share the same frame and merge. This creates the effect: a collision of two time planes or realities. Indispensable in horror or fantasy cinema. In drama, it's more of a stylistic device for poetry, not for psychological clarity — cuts and sound design are more honest for that.