1 The idea
Order the camera stack along the light’s path: through a filter in front of the lens (diffusion, with the main glow from LA4 alongside it), bouncing in the glass (flares, glints), the body shaking (shake), the glass splitting colour towards the edges (CA), and finally the film or sensor (halation, then grain last). The wrong order changes the picture: in the zoom, grain that went through diffusion or shake is blurred, which no real camera can do.
Focus breathing is the picture growing or shrinking a little as focus is pulled, because the lens’s real focal length shifts with it. If the plate breathes, CG and 2D elements must scale with it or they float. Switch to Focus breathing to see how far the edges move.
2 Hands-on
Task: order the 7 steps the way light travels through the camera
Flares and glints may swap: both are added light, and addition works in any order
3 Deep dive
Follow the light, from outside in
What sits in front of the lens happens first (diffusion from a filter or a smudge; the main glow from LA4 belongs here too). Then light bounces in the glass (flares and glints). The camera body shakes and carries the whole picture with it (shake). The glass splits colour more towards the edges (CA). Then the film or sensor (halation), and grain is the very last thing that happens to the picture.
| Step | If it’s in the wrong place |
|---|---|
| Diffusion / glow | After the flares: the flares get softened or bloomed when they shouldn’t |
| Flares / glints | After CA: the flares miss the lens’s colour fringe |
| Shake | After grain: grain gets smeared and travels with the picture |
| Halation | Before the flares: the flare light gets no red rim |
| Grain | Not last: it gets blurred, moved or recoloured |
Where sources disagree
Some sources put CA before the shake; some add lens distortion and vignette to the chain. Distortion of the CG is a separate job: it is put back on the CG branch before the merge (LA6), because the plate already carries the real lens. For the synthetic effects in this stack, ask whether an effect follows the scene or stays fixed to the frame. The shake moves the whole camera, so the scene slides within the frame. Effects that follow scene content (diffusion and glow around the lights, flares that track their source) go before the shake; effects fixed to the frame (CA, vignette, grain) don’t move with the scene, so they go after it. On a still frame the difference is tiny. What every source agrees on: grain last, glow/diffusion before the shake, vignette after distortion.
Flares and glints really can swap: both are added light, and A + B equals B + A. Diffusion, shake, CA and grain change the picture in ways that don’t commute.
Always judge the shot through the full camera stack
Focus breathing
Many lenses change their real focal length slightly as focus is pulled, so the picture grows or shrinks about the centre; direction and amount depend on the lens, and well-designed cine lenses breathe little. In the lab, 1.5% breathing moves the edge of an HD frame by 14.4 px, enough to make a 2D element that doesn’t scale look like it’s floating.
A camera solve usually reads breathing as a focal change (or a small dolly). Lens and focus-distance data from set helps a lot. For 2D elements, use a Transform that scales about the centre, tied to the focus curve.
4 In real work
In Nuke
- Keep the camera stack in one backdrop at the bottom of the script, after the (already redistorted) CG is merged with the plate, top to bottom: diffusion and the main glow → Flare/Glint → CameraShake → CA → halation → Grain.
- CA: TransformMasked per channel (red scaled up a hair, blue down a hair) about the centre, keeping the original brightness so only colour changes.
- CameraShake needs overscan, just like the redistort (LA6).
- Breathing: a Transform scaling about the centre, with an expression tied to the focus curve.
- Grain (or the third-party DasGrain gizmo) is the last node before the crop and the Write.
Common mistakes → the fix
- ✗ A grade or glow after the grain✓ Move it before the grain; after the grain only a crop and the Write.
- ✗ Shaking each element separately✓ Shake the whole frame once: it’s the camera that moves.
- ✗ CA so heavy the edges turn rainbow✓ Use very little; read it from bright edges in the plate.
- ✗ Ignoring breathing in a rack-focus shot✓ Measure the scaling in the plate and scale the CG/elements with the focus.
Before you send the shot
- Grain last; nothing after it but the crop and Write
- Halation right before grain and after CA
- Diffusion, the main glow and flares come before the shake
- Rack-focus shots: CG scales with the plate’s breathing
- Judged through the full camera stack
5 Check yourself
What happens if grain sits before the camera shake?
🔒 Answer the question above and this card opens
1. Does swapping flares and glints change the picture?
2. With 2% breathing on a 1920-wide plate, roughly how far does the frame edge move?
Where the numbers come from: This order comes from KB 159 and 153 (the camera order, outside in). Some sources put CA before the shake, or add lens distortion and vignette to the chain; every source agrees that grain goes last and glow/diffusion come before the shake. Every step here is exaggerated so you can see it. The breathing amount is an example; lenses differ a lot, so measure it from the plate.