diff --git a/web/calibrate/Light9Calibrate.ts b/web/calibrate/Light9Calibrate.ts
--- a/web/calibrate/Light9Calibrate.ts
+++ b/web/calibrate/Light9Calibrate.ts
@@ -81,7 +81,7 @@ export class Light9Calibrate extends Lit
   async findSafeExposure(ev: MouseEvent) {
     await this.withButtonSpinner(ev, async () => {
       const algo = new FindSafeExposure(this.cam!, this.plot!);
-      await algo.run();
+      const expo = await algo.run();
     });
   }
   async setToZero(ev: MouseEvent) {