diff --git a/web/calibrate/Light9Calibrate.ts b/web/calibrate/Light9Calibrate.ts
--- a/web/calibrate/Light9Calibrate.ts
+++ b/web/calibrate/Light9Calibrate.ts
@@ -4,15 +4,17 @@ import { customElement, query, state } f
 import { CollectorClient } from "../collector/CollectorClient";
 import { getTopGraph } from "../RdfdbSyncedGraph";
 import { SyncedGraph } from "../SyncedGraph";
+import { FindSafeExposure } from "./FindSafeExposure";
 import { Light9Camera } from "./Light9Camera";
 import { XyPlot } from "./XyPlot";
 export { RdfdbSyncedGraph } from "../RdfdbSyncedGraph";
 export { Light9Camera } from "./Light9Camera";
 export { XyPlot } from "./XyPlot";
+
 debug.enable("*");
 const log = debug("calibrate");
 
-async function sleep(ms: number) {
+export async function sleep(ms: number) {
   return new Promise((resolve) => setTimeout(resolve, ms));
 }
 
@@ -78,37 +80,8 @@ export class Light9Calibrate extends Lit
 
   async findSafeExposure(ev: MouseEvent) {
     await this.withButtonSpinner(ev, async () => {
-
-      const gatherSample = async (expo: number) => {
-        await this.cam?.set("exposureTime", expo);
-        const settleUntil = Date.now() + 1000;
-        let miny = this.cam?.saturatedPixelCount!;
-        while (Date.now() < settleUntil) {
-          await sleep(50);
-          miny = Math.min(miny, this.cam?.saturatedPixelCount!);
-        }
-        this.plot!.insertPoint(expo, miny);
-      };
-
-      // todo: drive around without big skips, gradually slower, looking for the max workable expo
-      let fixedSteps = 8;
-      const expoMin = 1;
-      const expoMax = 200;
-      let expo = 0;
-      const data=this.plot!.data;
-      while (data.length < 20) {
-        if (data.length < fixedSteps + 1) {
-          expo = expoMin + ((expoMax - expoMin) / fixedSteps) * data.length;
-        } else {
-          let x2 = data.findIndex(([_, y]) => y > 2);
-          if (x2 < 1) x2 = 1;
-          const x1 = x2 - 1;
-          log(JSON.stringify([x1, data[x1], x2, data[x2]]));
-          expo = (data[x1][0] + data[x2][0]) / 2;
-          log(data);
-        }
-        await gatherSample(expo);
-      }
+      const algo = new FindSafeExposure(this.cam!, this.plot!);
+      await algo.run();
     });
   }
   async setToZero(ev: MouseEvent) {