AI video looks fake because it lacks the imperfections a real camera imposes: sensor noise, lens character, uneven lighting falloff, and consistent physics. Generated frames are individually convincing but collectively unstable, so the eye registers small contradictions in texture, motion and light before the brain names them.
The specific tells worth hunting for:
Two of these — plastic surfaces and camera perfection — are fixable in post. The rest are cheaper to prevent at generation.
The largest quality jump comes from what you choose to generate, not what you clean up afterwards.
Start from an image, not a sentence. Image-to-video anchors skin texture, lighting physics and material properties to a frame that already looks real, so the model only has to add motion. Text-to-video makes it invent everything, and invention is where the AI look lives.
Prompt motion, not adjectives. “Cinematic, ultra-realistic, 8K” gives a model nothing to hold onto. “She turns her head slightly left, blinks, exhales; camera holds static” gives it a target. Describe the subject, the action, the light source and the camera behaviour separately.
Keep clips short. Most drift compounds with duration. Three to five seconds per generation, cut together, beats one long take that degrades halfway through.
Design around known weaknesses. Hands doing fine work, crowds, readable text, water pouring, and animals running are still expensive to get right. A steady subject in motivated, simple motion is not.
Reference real gear. Naming a plausible lens and format — a 50mm on 35mm film, a handheld phone clip — pushes output away from the glossy default that has become its own giveaway.
Flicker in generated video comes from temporal inconsistency: the model regenerates texture, colour and micro-detail slightly differently on every frame. At 24fps, those small differences read as a shimmer or a broken-projector pulse, usually strongest in still areas like walls, skin and hair.
Work through it in this order:
Raw generated footage is too clean, too flat and too uniform. Post is where you put back what a real camera would have added.
Grade with intent. Lift the blacks slightly so nothing crushes to pure black. Introduce a colour split between highlights and shadows. Real footage rarely has neutral shadows across the whole frame.
Add grain last, after the grade. Match the grain to a plausible stock or sensor, keep it visible but not decorative, and apply it over the whole frame so it unifies composited elements. Grain is the single most effective realism cue available in post because it reintroduces the sensor noise generators never produce.
Give the image a lens. A subtle vignette, a touch of chromatic aberration at the frame edges, and softening away from the focal plane break the edge-to-edge sharpness that flags AI immediately. Slight focus breathing on a push-in sells it further.
Conform the cadence. Export at a constant frame rate and stay at one standard — usually 24fps for narrative work. Frame-rate mismatches between generation, edit and delivery create judder that reads as synthetic. Add motion blur if the generator produced unnaturally crisp fast motion.
Resist over-sharpening. Upscalers that hallucinate detail will undo the work above. Upscale conservatively, and never stack a sharpening pass on top of a model that already invents texture.
Lip-sync problems in AI generated video usually come from one of four causes: the audio was generated after the visuals, the frame rate changed somewhere in the pipeline, the face is too small or too angled for the sync model to track, or the performance underneath the mouth is frozen while only the lips move.
The reliable workflow:
Sound carries realism more than most creators expect. Silent, roomless dialogue announces a synthetic origin instantly. Add room tone, footsteps, cloth movement, breath, and distance-appropriate ambience. A slightly imperfect image with convincing sound design will pass where a beautiful image with clean silence will not.
Two details separate an amateur mix from a believable one. First, reverb should match the space you appear to be in — a kitchen and a car park do not sound alike, and generated dialogue arrives with neither. Second, level should track distance: a subject walking away from camera gets quieter and duller, not just quieter. Both take minutes and buy more credibility than another round of regeneration.