diff --git a/src/main/java/org/micromanager/lightsheetmanager/gui/tabs/CameraTab.java b/src/main/java/org/micromanager/lightsheetmanager/gui/tabs/CameraTab.java
index b1c5dfc..e6c0141 100644
--- a/src/main/java/org/micromanager/lightsheetmanager/gui/tabs/CameraTab.java
+++ b/src/main/java/org/micromanager/lightsheetmanager/gui/tabs/CameraTab.java
@@ -198,7 +198,6 @@ private void computeCameraOrder() {
         //   but needs additional work to support 4. Use a reorderable JTable?
         for (int i = 0; i < cameraNames.length; i++) {
             if (!selected.equals(cameraNames[i])) {
-                System.out.println("cameraNames[i] " + cameraNames[i] + "active[i] " + active[i]);
                 cameraData.add(new CameraData(cameraNames[i], active[i]));
             }
         }
diff --git a/src/main/java/org/micromanager/lightsheetmanager/model/acquisitions/AcquisitionEngineSCAPE.java b/src/main/java/org/micromanager/lightsheetmanager/model/acquisitions/AcquisitionEngineSCAPE.java
index 42bdfa4..9edaab1 100644
--- a/src/main/java/org/micromanager/lightsheetmanager/model/acquisitions/AcquisitionEngineSCAPE.java
+++ b/src/main/java/org/micromanager/lightsheetmanager/model/acquisitions/AcquisitionEngineSCAPE.java
@@ -17,6 +17,7 @@
 import org.micromanager.data.internal.DefaultSummaryMetadata;
 import org.micromanager.internal.MMStudio;
 import org.micromanager.lightsheetmanager.api.data.AcquisitionMode;
+import org.micromanager.lightsheetmanager.api.data.CameraData;
 import org.micromanager.lightsheetmanager.api.data.CameraLibrary;
 import org.micromanager.lightsheetmanager.api.data.CameraMode;
 import org.micromanager.lightsheetmanager.api.data.MultiChannelMode;
@@ -43,7 +44,6 @@
 import java.awt.geom.Point2D;
 import java.io.IOException;
 import java.util.ArrayList;
-import java.util.stream.IntStream;
 
 
 public class AcquisitionEngineSCAPE extends AcquisitionEngine {
@@ -86,14 +86,22 @@ boolean setup() {
 //        }
 
         // we must have an active camera if we are using simultaneous cameras
-//        if (model_.acquisitions().settings().isUsingSimultaneousCameras()) {
-//            final boolean[] active = model_.acquisitions().settings().imagingCamerasActive();
-//            if (IntStream.range(0, active.length).noneMatch(i -> active[i])) {
-//                studio_.logs().showError("Using simultaneous cameras and no cameras are active!");
-//                return false;
-//            }
-//            // TODO: primary camera must be active
-//        }
+        if (model_.acquisitions().settings().isUsingSimultaneousCameras()) {
+            final CameraData[] cameras = model_.acquisitions().settings().imagingCameraOrder();
+            if (cameras.length > 0 && !cameras[0].isActive()) {
+                studio_.logs().showError("The primary camera MUST be active in simultaneous cameras mode!");
+                return false;
+            }
+            // set the core camera device to the primary camera
+            if (cameras.length > 1) {
+                try {
+                    core_.setCameraDevice(cameras[0].name());
+                } catch (Exception e) {
+                    studio_.logs().showError("Could not set \"Core-Camera\" for simultaneous cameras.");
+                    return false;
+                }
+            }
+        }
 
         // this is needed for LSMAcquisitionEvents to work with multiple positions
         if (core_.getFocusDevice().isEmpty()