ImageEffectsLensZoomBurst

A zoom burst is that streaky motion look you get when you zoom the lens mid-exposure - everything blasts outward from the center like a speed-force field. ImageEffectsLensZoomBurst from the Allor plugin reproduces it by stacking a whole series of scaled copies of the image and blending them together. It's the most "expensive" node in this pack's lens section, but it's also the one that produces something you genuinely can't fake with a single blur.

How it works

The node's core loop takes the image, progressively scales it up (and optionally rotates it) from the burst center outward, and averages the frames. The inputs control that stack:

• scale - how far the burst stretches (1.0 = no effect; 1.5 is a solid speed streak).
• samples - how many intermediate frames get blended (default 100). More samples = smoother, slower.
• position_x / position_y - where the burst center sits, as 0–1 fractions. Default 0.5/0.5 puts it dead center.
• rotation - degrees of twist across the burst. 0 gives a pure radial zoom; anything above 0 adds a vortex feel.
• method - circle (streaks radiate with a circular falloff, more lens-like) or point (pure straight radial lines from the center).
• stabilization - true blends both inward and outward frames symmetrically for a steadier, more cinematic streak; false only zooms outward for a punchier directional burst.

Under the hood it uses OpenCV remap/warpAffine on numpy arrays, one frame per sample, then averages. That's the real cost: 100 remaps per image, on the CPU.

Output is a single IMAGE, same dimensions as the input.

Installing it

It ships with the Allor pack:

cd ComfyUI/custom_nodes
git clone https://github.com/Nourepide/ComfyUI-Allor

Restart ComfyUI, or use ComfyUI Manager → Allor Plugin. First boot installs rembg + onnx and creates the pack's config.json; no model downloads for this node.

Gotchas

• It's slow. samples at 100 on a big image is a real wait. Drop to 30–50 first - you lose very little smoothness and gain a lot of speed. And it's per-image, so a batch of 8 is 8× the pain.
• The effect is subtle at scale near 1. If your burst looks like nothing happened, raise scale before you raise samples.
• With stabilization off, the streaks favor one direction and can look a touch directional; flip it on for a more neutral radial look.
• Pack-wide update gotcha as always: Allor's repo was rebased to shrink history, so old clones can fail on git pull - re-clone if auto-update errors.

Combine a light zoom burst with ImageEffectsLensVignette and you have the classic "action shot" finish.