diff --git a/headers/MainWindow.h b/headers/MainWindow.h
index ea0a868..8466fff 100644
--- a/headers/MainWindow.h
+++ b/headers/MainWindow.h
@@ -8,7 +8,7 @@ class MainWindow : public QWidget {
 public:
 	explicit MainWindow();
 private slots:
-	void sizeSliderChanged(int);
+	void iterationsSliderChanged(int);
 private:
 	void buildUI();
 
diff --git a/headers/Mandelbrot.h b/headers/Mandelbrot.h
index 374dc12..acf5d0f 100644
--- a/headers/Mandelbrot.h
+++ b/headers/Mandelbrot.h
@@ -4,13 +4,17 @@
 #include <QVector2D>
 #include <QOpenGLFunctions>
 
-class Mandelbrot : protected QOpenGLFunctions {
+class Mandelbrot : public QObject, protected QOpenGLFunctions {
+Q_OBJECT
 public:
-	Mandelbrot();
+	void init();
 	void draw();
 	void zoom(double);
+public slots:
+	void setIterations(int);
 private:
-	double scale;
+	int iterations = 0;
+	double scale = 1;
 	QVector2D translation;
 };
 
diff --git a/headers/OutputWidget.h b/headers/OutputWidget.h
index 7c0b6cf..5e8b041 100644
--- a/headers/OutputWidget.h
+++ b/headers/OutputWidget.h
@@ -10,7 +10,8 @@
 class OutputWidget : public QOpenGLWidget, protected QOpenGLFunctions {
 	Q_OBJECT
 public:
-	explicit OutputWidget(QWidget* parent): QOpenGLWidget(parent) {};
+	explicit OutputWidget(QWidget* parent): QOpenGLWidget(parent) {}
+	Mandelbrot* getMandelbrot() {return &mandelbrot;}
 private:
 	void initializeGL() override;
 	void paintGL() override;
diff --git a/src/MainWindow.cpp b/src/MainWindow.cpp
index 12c5611..2ed7417 100644
--- a/src/MainWindow.cpp
+++ b/src/MainWindow.cpp
@@ -10,20 +10,32 @@ MainWindow::MainWindow() {
 void MainWindow::buildUI() {
 	resize(700, 700);
 
-	auto sizeSlider = new QSlider(Qt::Horizontal);
-	sizeSlider->setRange(100, 800);
-	QSlider::connect(sizeSlider, &QSlider::valueChanged, this, &MainWindow::sizeSliderChanged);
-	sizeSlider->setValue(500);
+	auto iterationsSlider = new QSlider(Qt::Horizontal);
+	iterationsSlider->setRange(5, 300);
+	QSlider::connect(
+			iterationsSlider,
+			&QSlider::valueChanged,
+			this->outputWidget->getMandelbrot(),
+			&Mandelbrot::setIterations
+			);
+	QSlider::connect(
+			iterationsSlider,
+			&QSlider::valueChanged,
+			this,
+			&MainWindow::iterationsSliderChanged
+			);
+
+	iterationsSlider->setValue(100);
 
 	auto controls = new QGridLayout;
-	controls->addWidget(sizeSlider);
+	controls->addWidget(iterationsSlider);
 
 	auto lyt = new QVBoxLayout(this);
 	lyt->addWidget(outputWidget);
 	lyt->addLayout(controls);
 }
 
-//TODO Handle size change
-void MainWindow::sizeSliderChanged(int newValue) {
-
+void MainWindow::iterationsSliderChanged(int newValue) {
+	//TODO update text label
+	update();
 }
diff --git a/src/Mandelbrot.cpp b/src/Mandelbrot.cpp
index 53405f7..e05bfcf 100644
--- a/src/Mandelbrot.cpp
+++ b/src/Mandelbrot.cpp
@@ -1,8 +1,10 @@
 
 #include "../headers/Mandelbrot.h"
 
-Mandelbrot::Mandelbrot() {
+void Mandelbrot::init() {
 	initializeOpenGLFunctions();
+
+
 }
 
 void Mandelbrot::draw() {
@@ -10,5 +12,11 @@ void Mandelbrot::draw() {
 }
 
 void Mandelbrot::zoom(double delta) {
+	scale *= delta;
+}
 
+void Mandelbrot::setIterations(int value) {
+	iterations = value;
 }
+
+
diff --git a/src/OutputWidget.cpp b/src/OutputWidget.cpp
index b6f2ed2..b5b7e5b 100644
--- a/src/OutputWidget.cpp
+++ b/src/OutputWidget.cpp
@@ -7,18 +7,17 @@ using std::cout, std::endl;
 void OutputWidget::initializeGL() {
 	cout << "Initialize OpenGL" << endl;
 	initializeOpenGLFunctions();
+	getMandelbrot()->init();
 
 	auto format = this->format();
-	cout << "OpenGL version: " <<
-		format.majorVersion() << "." << format.minorVersion()
-	<< endl;
+	cout << "OpenGL version: " << format.majorVersion() << "." << format.minorVersion() << endl;
 
 	glClearColor(0.5f, 0.5f, 0.5f, 1.0f);
 }
 
 void OutputWidget::paintGL() {
 	glClear(GL_COLOR_BUFFER_BIT);
-	mandelbrot.draw();
+	getMandelbrot()->draw();
 }
 
 void OutputWidget::resizeGL(int w, int h) {