Thermal
Thermal imaging cinematography maps emitted long-wave infrared (heat), not reflected light. A microbolometer or similar sensor assigns a palette (white-hot, black-hot, ironbow) to temperature, so faces, engines, and blood read warm while cold metal and night air do not.
Narrative function
You are not lighting the scene. You are reading temperature.
A body is a mask. A recently used gun is a bright shape.
Walls may be dark. Visible lamps do not necessarily dominate.
The camera is forensic or predatory. Use it when the story is heat: a hunter's vision, search and rescue, a border raid, an alien targeting system.
The palette is a legend, not a grade. It is the wrong tool for green goggle work or for pale-leaf IR photography.
If lamps bloom and the room is grainy green, that is night vision. If foliage is white under a black sky, that is near-IR stills.
How it works
No key light in the usual sense. Contrast is delta-T.
Choose a palette and keep it consistent. Warm cores, cooler edges, possible bloom on the hottest spots.
Glass windows can block LWIR, so a face behind glass may fail. Prompt: thermal palette, heat as color, faces as warm masks, not green phosphor, not near-IR foliage.
When to use it
A rider and horse as warm shapes on a cold ridge, ironbow or white-hot, breath as a plume, stone dark. Do not render it as a green night-vision feed or as daylight IR woods.
Compared with similar shots
Night Vision intensifies residual light on a phosphor. Infrared photographs near-IR reflectance (white leaves, dark sky).
Thermal is emitted LWIR. Monochrome is visible-light grey.
A thermal image can look mono in white-hot, but its tones follow heat, not albedo.
In film
Predator makes heat the alien's sight: bodies as warm figures in a cool jungle. Sicario uses thermal and related electro-optical views as raid and border seeing.
Those are device palettes, not looks to photocopy.
Prompt it
Map temperature, not lamps. Example: Thermal palette of [Subject], heat as color, faces as warm masks, ironbow or white-hot, search-and-rescue or predator vision, not night-vision green, not pale infrared foliage.
What usually goes wrong
Wrong cousin: night vision or near-IR photography. Tell: green grain with blooming streetlights, or white trees and black sky, or normal modeling from a key light.
Fix: temperature-based tones, warm bodies, cold surroundings, a named palette.
Questions
What is thermal in film?
An image of emitted heat mapped to a false-color or white-hot palette. It records temperature, not the light a normal camera would see.
Thermal vs night vision
Night vision amplifies light and usually looks green and grainy. Thermal paints heat. A cold dark room can still show a warm body on thermal.
When should I use thermal?
When the beat is temperature: hunting, rescue, targeting. Do not use it as a sci-fi grade on a normally lit scene.
How do I prompt thermal for AI image or video?
Name the palette (ironbow, white-hot), say heat as color, warm faces, cool environment. Forbid green phosphor and near-IR foliage looks.
Melies can generate this Thermal
Melies is the AI filmmaking workspace. This Thermal opens with the optical prompt loaded, so the effect has a physical cause in the frame.