Unwanted digital byproduct from compression, rendering, or motion blur — banding, aliasing, ghosting. Kills credibility in final output.
Everything looks clean on the monitor — then comes the first DCP test, and suddenly stripes appear in the sky, strange edges around moving objects, or double contours that weren't there before. These are Artifacts, and they don't arise from creative failure, but from the way digital systems calculate, store, and compress images.
Artifacts are unwanted visual side effects that occur during rendering, encoding, or motion processing. The most common culprits: Banding (visible color stripes instead of a color gradient, especially in grades), Aliasing (jagged edges on diagonal lines or fine geometry), Ghosting (double images with motion blur or temporal upsampling), and Compression Artifacts (blocky structures, ringing around edges). In the DI process, they become an obsession — because they look grotesque on a 15-meter screen in the cinema, but are barely noticeable on the editing monitor.
In practice, the problem often arises in the rendering pipeline: overly aggressive compression (H.265, ProRes), incorrect color depth (8-bit instead of 10-bit for grades), or sloppily configured motion blur in 3D software. When upsampling from a lower to a higher resolution, ghosting effects occur if the interpolation is not temporally consistent. Faulty keying operations (especially with fine details like hair) also produce halos and fringes — technically artifacts, but with a different cause than rendering errors.
The countermeasures are simple once you know them: Always work in 10-bit or higher, especially for color grades and VFX plates. Set Motion Blur and Temporal Anti-Aliasing correctly in the render engine (don't skimp, don't overdo it). When exporting: choose conservative codec settings — prefer ProRes HQ over aggressive H.265 if compositing is still pending. In the color grade, subtly smooth problematic areas with dithering (not visible, but effective). And always perform a critical QC pass before the final DCP — artifacts are correctable, but only after they've been spotted.
Anyone who ignores artifacts risks them becoming the center of attention during projection. They are distracting, look cheap, and destroy credibility, especially in elaborate VFX shots. Clean output is not a creative compromise, but technical diligence.