diff --git a/main.cpp b/main.cpp
index b6a0e60..06bcad2 100644
--- a/main.cpp
+++ b/main.cpp
@@ -1,4 +1,5 @@
 #include <QApplication>
+#include <QtGlobal>
 
 #include "mainwindow.h"
 
@@ -6,6 +7,17 @@ int main(int argc, char *argv[])
 {
     QApplication a(argc, argv);
 
+    qSetMessagePattern(QStringLiteral("%{time dd.MM.yyyy HH:mm:ss.zzz} "
+                                      "["
+                                      "%{if-debug}D%{endif}"
+                                      "%{if-info}I%{endif}"
+                                      "%{if-warning}W%{endif}"
+                                      "%{if-critical}C%{endif}"
+                                      "%{if-fatal}F%{endif}"
+                                      "] "
+                                      "%{function}(): "
+                                      "%{message}"));
+
     MainWindow mainWindow;
     mainWindow.show();
 
diff --git a/mainwindow.cpp b/mainwindow.cpp
index 7c2b7bc..60c299a 100644
--- a/mainwindow.cpp
+++ b/mainwindow.cpp
@@ -30,6 +30,9 @@ MainWindow::MainWindow(QWidget *parent)
         }
     }
 
+    if (m_ui.comboBoxDevices->count())
+        m_ui.comboBoxDevices->setCurrentIndex(m_audioDevices.count()-1);
+
     for (const auto samplerate : { 44100, 48000, 96000, 192000 })
         m_ui.comboBoxSamplerate->addItem(tr("%0").arg(samplerate), samplerate);
 
@@ -48,6 +51,10 @@ MainWindow::MainWindow(QWidget *parent)
 
     connect(m_ui.spinBoxBlend, qOverload<int>(&QSpinBox::valueChanged), m_ui.widget, &OsciWidget::setBlend);
 
+    m_ui.spinBoxGlow->setValue(m_ui.widget->glow());
+
+    connect(m_ui.spinBoxGlow, qOverload<int>(&QSpinBox::valueChanged), m_ui.widget, &OsciWidget::setGlow);
+
     auto buttonGroup = new QButtonGroup;
     buttonGroup->setExclusive(true);    
     for (auto factor : { .5f, 1.f, 2.f, 4.f, 8.f })
diff --git a/mainwindow.ui b/mainwindow.ui
index 6f5c674..cc07513 100644
--- a/mainwindow.ui
+++ b/mainwindow.ui
@@ -75,6 +75,16 @@
         </property>
        </widget>
       </item>
+      <item>
+       <widget class="QSpinBox" name="spinBoxGlow">
+        <property name="suffix">
+         <string> glow</string>
+        </property>
+        <property name="maximum">
+         <number>65535</number>
+        </property>
+       </widget>
+      </item>
       <item>
        <spacer name="horizontalSpacer_2">
         <property name="orientation">
diff --git a/osciwidget.cpp b/osciwidget.cpp
index 97a82d0..23652d1 100644
--- a/osciwidget.cpp
+++ b/osciwidget.cpp
@@ -26,12 +26,17 @@ float OsciWidget::factor() const
     return m_factor;
 }
 
+float OsciWidget::glow() const
+{
+    return m_glow;
+}
+
 void OsciWidget::setFramerate(int framerate)
 {
     if (framerate == m_framerate)
         return;
 
-    qDebug() << "change framerate to" << framerate;
+    qDebug() << framerate;
 
     m_framerate = framerate;
 
@@ -43,16 +48,23 @@ void OsciWidget::setBlend(int blend)
     if (blend == m_blend)
         return;
 
-    qDebug() << "change blend to" << blend;
+    qDebug() << blend;
 
     m_blend = blend;
 }
 
 void OsciWidget::setFactor(float factor)
 {
+    qDebug() << factor;
     m_factor = factor;
 }
 
+void OsciWidget::setGlow(float glow)
+{
+    qDebug() << glow;
+    m_glow = glow;
+}
+
 void OsciWidget::renderSamples(const SamplePair *begin, const SamplePair *end)
 {
     QPainter painter;
@@ -69,19 +81,30 @@ void OsciWidget::renderSamples(const SamplePair *begin, const SamplePair *end)
 
     for (auto i = begin; i < end; i++)
     {
-        const qreal x = (qreal(i->x) / std::numeric_limits<qint16>::max() / 2 * width() / 2 * m_factor);
-        const qreal y = (qreal(i->y) / std::numeric_limits<qint16>::max() / 2 * height() / 2 * m_factor);
-        const QPointF p{x, y};
+        const QPointF p{
+            float(i->x) / std::numeric_limits<qint16>::max() / 2,
+            float(-i->y) / std::numeric_limits<qint16>::max() / 2
+        };
 
         if (Q_LIKELY(m_lastPoint.has_value()))
         {
-            auto speed = QLineF(*m_lastPoint, p).length();
-            if (speed < 1)
-                speed = 1;
-            auto brightness = 1./speed;
+            const QLineF line(*m_lastPoint, p);
+            
+            auto brightness = 1.f / line.length() / m_glow;
+            if (line.length() == 0.f || brightness > 255.f)
+                brightness = 255.f;
 
             painter.setOpacity(brightness);
-            painter.drawLine(*m_lastPoint, p);
+
+            const auto pointToCoordinates = [this](const QPointF &point)
+            {
+                return QPoint{
+                    int((point.x() * width() / 2 * m_factor)),
+                    int((point.y() * height() / 2 * m_factor))
+                };
+            };
+
+            painter.drawLine(pointToCoordinates(*m_lastPoint), pointToCoordinates(p));
         }
 
         m_lastPoint = p;
diff --git a/osciwidget.h b/osciwidget.h
index 77a75a8..c064e07 100644
--- a/osciwidget.h
+++ b/osciwidget.h
@@ -24,6 +24,8 @@ public:
     int framerate() const;
     int blend() const;
     float factor() const;
+    float glow() const;
+    
     void start();
     void stop();
 
@@ -31,6 +33,7 @@ public slots:
     void setFramerate(int framerate);
     void setBlend(int blend);
     void setFactor(float factor);
+    void setGlow(float glow);
 
     void renderSamples(const SamplePair *begin, const SamplePair *end);
 
@@ -46,8 +49,9 @@ private:
 
     int m_timerId{-1};
     int m_framerate{15};
-    int m_blend{190};
+    int m_blend{150};
     float m_factor{4.f};
+    float m_glow{512.f};
 
     QPixmap m_pixmap;