diff --git a/crates/visaged/src/engine.rs b/crates/visaged/src/engine.rs
index 274c649..b92e600 100644
--- a/crates/visaged/src/engine.rs
+++ b/crates/visaged/src/engine.rs
@@ -164,12 +164,15 @@ pub fn spawn_engine(
         None
     };
 
-    // Discard warmup frames for camera AGC/AE stabilization
+    // Discard warmup frames for camera AGC/AE stabilization — with the emitter
+    // active, in one continuous stream. Auto-gain only adapts while streaming;
+    // warming up against ambient light leaves it high, and the first lit
+    // capture after start is then saturated white and fails detection.
     if warmup_frames > 0 {
         tracing::info!(count = warmup_frames, "discarding warmup frames");
-        for _ in 0..warmup_frames {
-            let _ = camera.capture_frame();
-        }
+        activate_emitter(&emitter);
+        let _ = camera.capture_frames(warmup_frames);
+        deactivate_emitter(&emitter);
     }
 
     let (tx, mut rx) = mpsc::channel::<EngineRequest>(4);
diff --git a/docs/operations-guide.md b/docs/operations-guide.md
index 298e992..e6a0f9e 100644
--- a/docs/operations-guide.md
+++ b/docs/operations-guide.md
@@ -322,6 +322,7 @@ Environment=VARIABLE=value
 | `VISAGE_VERIFY_TIMEOUT_SECS` | `10` | Max seconds for a verify attempt |
 | `VISAGE_FRAMES_PER_VERIFY` | `3` | Frames captured per authentication |
 | `VISAGE_FRAMES_PER_ENROLL` | `5` | Frames captured per enrollment |
+| `VISAGE_WARMUP_FRAMES` | `4` | Usable frames discarded at daemon start, captured with the IR emitter active so auto-gain settles against it. Raise it if the first verify after start fails and later ones work. |
 | `VISAGE_EMITTER_ENABLED` | `1` | Set to `0` to disable IR emitter |
 | `VISAGE_LIVENESS_ENABLED` | `1` | Set to `0` to disable passive liveness detection (development only) |
 | `VISAGE_LIVENESS_MIN_DISPLACEMENT` | `0.8` | Minimum eye landmark displacement (px) for liveness check |