Warp, Blend & Black Level
Making the projected image correct on the screen: geometry first, then the seams between projectors, then — if the content needs it — the black floor.
This stage applies to projection. A display shows content directly and needs none of it.
Lighting is the precondition for every camera-based job here.
Alignment needs light that is dark and constant. Dark, so the projected patterns stand out. Constant, so every photo in a run is comparable — the solver matches patterns across captures taken minutes apart, and light that changes between them corrupts the result.
Black level needs complete darkness. You are measuring how much light a projector emits while showing black, so any ambient light is measured along with it.
"Constant" is the half people miss: daylight moving over a run, a door opened mid-capture, motion-triggered building lighting. A room can be dark enough and still fail.
1. Get a correct grid on screen
Do one of these — they are alternatives, not steps:
Route | Pick it when |
|---|---|
Few projectors, no camera available, or fine-tuning a calibrated result by hand. Also the base warp modes — planar, cylindrical, toroidal. | |
One camera, on a planar or cylindrical screen. Built into Backstage, no extra licence. Generates warp meshes and projector frustums automatically. | |
A multi-projector panorama aligned by hand, built up in passes from the corners inwards, where camera calibration is not available. | |
The external Calibrator, or Scalable Display Manager — see More options | Multiple cameras, any screen shape, black level compensation, or an existing calibration to import. |
Done when: a test grid is continuous across the seams and reaches the edges of the screen — whichever route produced it.
2. Blend the overlaps
Where projectors overlap, both are lighting the same pixels. Blending ramps each one down across the overlap so the join is invisible.
3. Black level — optional
Decide whether you need this at all. Content that is continuously bright does not: nobody is looking at the black floor of an image that is never black. It earns its cost on dark content, where the overlaps read as visibly brighter patches on an otherwise black screen.
When you do want it, it is measured with a camera — CalibratorLite's Black Level tab, or the external Calibrator. There is no by-hand alternative worth attempting: DLP projectors emit bright but unreachable pixels outside the usable pixel area, so the content side cannot compensate for light it cannot address.
More options
The external Calibrator's black level procedure, dome calibration, importing a Scalable Display Manager result, and applying a blend mask by hand:
Warp, Blend, Black Level: More Options
Next
Content — bringing media into the project
Playback — putting it on a timeline and running it