diff --git a/app/widget/viewer/viewer.cpp b/app/widget/viewer/viewer.cpp
index f6a71f333..49f260dd4 100644
--- a/app/widget/viewer/viewer.cpp
+++ b/app/widget/viewer/viewer.cpp
@@ -321,7 +321,8 @@ void ViewerWidget::SetFullScreen(QScreen *screen)
   connect(vw->display_widget(), &ViewerDisplayWidget::customContextMenuRequested, this, &ViewerWidget::ShowContextMenu);
 
   if (GetConnectedNode()) {
-    vw->SetResolution(GetConnectedNode()->video_params().width(), GetConnectedNode()->video_params().height());
+    vw->SetVideoParams(GetConnectedNode()->video_params());
+    vw->display_widget()->SetDeinterlacing(vw->display_widget()->IsDeinterlacing());
   }
 
   vw->display_widget()->SetImage(display_widget_->last_loaded_buffer());
@@ -1086,7 +1087,9 @@ void ViewerWidget::SetViewerPixelAspect(const rational &ratio)
 {
   sizer_->SetPixelAspectRatio(ratio);
 
-  // FIXME: Update windows too
+  foreach (ViewerWindow* vw, windows_) {
+    vw->SetPixelAspectRatio(ratio);
+  }
 }
 
 void ViewerWidget::LengthChangedSlot(const rational &length)
@@ -1108,7 +1111,9 @@ void ViewerWidget::InterlacingChangedSlot(VideoParams::Interlacing interlacing)
   // Automatically set a "sane" deinterlacing option
   display_widget_->SetDeinterlacing(interlacing != VideoParams::kInterlaceNone);
 
-  // FIXME: Set windows too
+  foreach (ViewerWindow* vw, windows_) {
+    vw->display_widget()->SetDeinterlacing(interlacing != VideoParams::kInterlaceNone);
+  }
 }
 
 void ViewerWidget::UpdateRendererVideoParameters()
diff --git a/app/widget/viewer/viewerwindow.cpp b/app/widget/viewer/viewerwindow.cpp
index 983d4289b..525e992be 100644
--- a/app/widget/viewer/viewerwindow.cpp
+++ b/app/widget/viewer/viewerwindow.cpp
@@ -28,7 +28,8 @@
 OLIVE_NAMESPACE_ENTER
 
 ViewerWindow::ViewerWindow(QWidget *parent) :
-  QWidget(parent, Qt::Window | Qt::WindowStaysOnTopHint)
+  QWidget(parent, Qt::Window | Qt::WindowStaysOnTopHint),
+  pixel_aspect_(1)
 {
   QVBoxLayout* layout = new QVBoxLayout(this);
   layout->setMargin(0);
@@ -43,23 +44,28 @@ ViewerDisplayWidget *ViewerWindow::display_widget() const
   return display_widget_;
 }
 
+void ViewerWindow::SetVideoParams(const VideoParams &params)
+{
+  width_ = params.width();
+  height_ = params.height();
+  pixel_aspect_ = params.pixel_aspect_ratio();
+
+  UpdateMatrix();
+}
+
 void ViewerWindow::SetResolution(int width, int height)
 {
-  // Set GL widget matrix to maintain this texture's aspect ratio
-  double window_ar = static_cast<double>(this->width()) / static_cast<double>(this->height());
-  double image_ar = static_cast<double>(width) / static_cast<double>(height);
+  width_ = width;
+  height_ = height;
 
-  QMatrix4x4 mat;
+  UpdateMatrix();
+}
 
-  if (window_ar > image_ar) {
-    // Window is wider than image, adjust X scale
-    mat.scale(image_ar / window_ar, 1.0f, 1.0f);
-  } else if (window_ar < image_ar) {
-    // Window is taller than image, adjust Y scale
-    mat.scale(1.0f, window_ar / image_ar, 1.0f);
-  }
+void ViewerWindow::SetPixelAspectRatio(const rational &pixel_aspect)
+{
+  pixel_aspect_ = pixel_aspect;
 
-  display_widget_->SetMatrix(mat);
+  UpdateMatrix();
 }
 
 void ViewerWindow::Play(const int64_t& start_timestamp, const int& playback_speed, const rational &timebase)
@@ -115,4 +121,23 @@ void ViewerWindow::UpdateFromQueue()
   }
 }
 
+void ViewerWindow::UpdateMatrix()
+{
+  // Set GL widget matrix to maintain this texture's aspect ratio
+  double window_ar = static_cast<double>(this->width()) / static_cast<double>(this->height());
+  double image_ar = static_cast<double>(width_) / static_cast<double>(height_) * pixel_aspect_.toDouble();
+
+  QMatrix4x4 mat;
+
+  if (window_ar > image_ar) {
+    // Window is wider than image, adjust X scale
+    mat.scale(image_ar / window_ar, 1.0f, 1.0f);
+  } else if (window_ar < image_ar) {
+    // Window is taller than image, adjust Y scale
+    mat.scale(1.0f, window_ar / image_ar, 1.0f);
+  }
+
+  display_widget_->SetMatrix(mat);
+}
+
 OLIVE_NAMESPACE_EXIT
diff --git a/app/widget/viewer/viewerwindow.h b/app/widget/viewer/viewerwindow.h
index 2f7742c9f..289f0ea87 100644
--- a/app/widget/viewer/viewerwindow.h
+++ b/app/widget/viewer/viewerwindow.h
@@ -36,11 +36,24 @@ public:
 
   ViewerDisplayWidget* display_widget() const;
 
+  /**
+   * @brief Used to adjust resulting picture to be the right aspect ratio
+   *
+   * Equivalent to calling SetResolution and SetPixelAspectRatio, just slightly faster since we
+   * only calculate the matrix once rather than twice.
+   */
+  void SetVideoParams(const VideoParams &params);
+
   /**
    * @brief Used to adjust resulting picture to be the right aspect ratio
    */
   void SetResolution(int width, int height);
 
+  /**
+   * @brief Used to adjust resulting picture to be the right aspect ratio
+   */
+  void SetPixelAspectRatio(const rational& pixel_aspect);
+
   ViewerQueue* queue() {
     return &queue_;
   }
@@ -58,6 +71,8 @@ private slots:
   void UpdateFromQueue();
 
 private:
+  void UpdateMatrix();
+
   ViewerDisplayWidget* display_widget_;
 
   ViewerQueue queue_;
@@ -66,6 +81,12 @@ private:
 
   rational playback_timebase_;
 
+  int width_;
+
+  int height_;
+
+  rational pixel_aspect_;
+
 };
 
 OLIVE_NAMESPACE_EXIT