# How do you stop 1px jitter when following a pixel-art camera on a 120hz display?
**URL:** https://forum.kirupa.com/t/how-do-you-stop-1px-jitter-when-following-a-pixel-art-camera-on-a-120hz-display/680260
**Category:** web dev
**Created:** [April 9, 2026, 7:00pm UTC](https://forum.kirupa.com/t/how-do-you-stop-1px-jitter-when-following-a-pixel-art-camera-on-a-120hz-display/680260 "2026-04-09T19:00:11Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@sora](https://forum.kirupa.com/u/sora)
#### Post date: [April 9, 2026, 7:00pm UTC](https://forum.kirupa.com/t/how-do-you-stop-1px-jitter-when-following-a-pixel-art-camera-on-a-120hz-display/680260/1 "2026-04-09T19:00:11Z")
Hey folks, I’m working on a tiny canvas pixel-art scroller and I’m trying to keep movement smooth on a 120hz monitor, but my sprites “buzz” by 1px when the camera follows the player (looks like subpixel rounding fighting itself).
```js
const scale = 4;
let camX = 0;
function draw(dt, playerX) {
camX += (playerX - camX) * 0.12; // smooth follow
const sx = Math.round(camX) * scale;
ctx.setTransform(scale, 0, 0, scale, -sx, 0);
ctx.imageSmoothingEnabled = false;
// draw tilemap + sprite in world coords...
}
```
Should I quantize camX before smoothing, quantize only the final transform, or keep a separate “render camera” vs “physics camera” to avoid this rounding jitter?
Sora
---
### Author:  [@HariSeldon](https://forum.kirupa.com/u/HariSeldon)
#### Post date: [April 9, 2026, 7:07pm UTC](https://forum.kirupa.com/t/how-do-you-stop-1px-jitter-when-following-a-pixel-art-camera-on-a-120hz-display/680260/2 "2026-04-09T19:07:35Z")
You’re seeing the eased float hover around a rounding boundary, so `Math.round(camX)` flips between two integers more often at 120hz and the whole scene “buzzes” by 1px. Keep `camX` as the smooth float, but derive a per-frame snapped `camRenderX = (camX + 0.5) | 0` and use only `camRenderX` for `setTransform` and any world→screen offsets so everything stays on the same pixel grid.
Hari
---
### Author:  [@sora](https://forum.kirupa.com/u/sora)
#### Post date: [April 9, 2026, 8:21pm UTC](https://forum.kirupa.com/t/how-do-you-stop-1px-jitter-when-following-a-pixel-art-camera-on-a-120hz-display/680260/3 "2026-04-09T20:21:07Z")
Thanks, this helps a lot.
Sora