diff --git a/src/cameramanager.cpp b/src/cameramanager.cpp
index 8c52d20..5cfbc2d 100644
--- a/src/cameramanager.cpp
+++ b/src/cameramanager.cpp
@@ -49,10 +49,12 @@ void CameraManager::connectCamera(unsigned int index) {
 
 // The capture callback is a wrapper to emit the frameCaptured signal.
 void CameraManager::captureCallback(FlyCapture2::Image* image, const void *camManager) {
+    lock.lock();
     if(camManager) {
         static_cast<const CameraManager*>(camManager)->frameCaptured(image);
     }
     qDebug() << "here";
+    lock.unlock();
     return;
 }
 
diff --git a/src/cameramanager.h b/src/cameramanager.h
index d0ce2c0..4325681 100644
--- a/src/cameramanager.h
+++ b/src/cameramanager.h
@@ -11,6 +11,7 @@
 // TODO: implement camera arrival removal
 #include <QObject>
 #include "FlyCapture2.h"
+#include <QMutex>
 
 class CameraManager : public QObject
 {
@@ -24,7 +25,7 @@ public:
 	// Throws FlyCapture2::Error
 	void startCapture();
 	void stopCapture();
-       
+
 	//TODO remove, if not needed
 	const FlyCapture2::Camera* getCamera() const {
 		return &camera;
@@ -67,6 +68,9 @@ private:
 	// State Variable
 	bool is_capturing;
 	
+    // Make captureCallback thread safe
+    static QMutex lock;
+
 signals:
     void frameCaptured(FlyCapture2::Image* image) const;
 };
diff --git a/src/mainwindow.cpp b/src/mainwindow.cpp
index 47843fa..837bea5 100644
--- a/src/mainwindow.cpp
+++ b/src/mainwindow.cpp
@@ -126,12 +126,10 @@ void MainWindow::toggle_preview(bool checked) {
 }
 
 void MainWindow::frame_captured(FlyCapture2::Image* image) {
-    test.lock();
     qDebug() << "Image Captured!";
-    // If preview is activated...
-//    if(ui->preview_widget->isVisible())
-//        displayPreview(image);
-    test.unlock();
+     If preview is activated...
+    if(ui->preview_widget->isVisible())
+        displayPreview(image);
     return;
 }
 
diff --git a/src/recorder.cpp b/src/recorder.cpp
index a51388e..9955301 100644
--- a/src/recorder.cpp
+++ b/src/recorder.cpp
@@ -135,7 +135,7 @@ void Recorder::cleanup() {
 
 void Recorder::appendFrame(FlyCapture2::Image *image) {
     write_lock.lock();
-	// If not recording, just stop.
+    // If not recording, just stop.
 	if(!is_recording)
 		return;