Parameter is not valid when creating Bitmap of size 6000X4500 Pixels

It's all about memory usage. I have done a small test, and here is the result. I create only a 500x500 Bitmap, but many times, without disposing it:

private void button1_Click(object sender, EventArgs e)
{
    int maxIterations = 5000;
    bool exceptionOccured = false;
    for (int i = 0; i < maxIterations; i++)
    {
        Bitmap bitmap = null;
        try
        {
            bitmap = new Bitmap(500, 500);
        }
        catch (Exception ex)
        {
            MessageBox.Show("Exception after " + i.ToString() + " iterations" + Environment.NewLine + ex.Message);
            exceptionOccured = true;
            break;
        }
        finally
        {
            //dispose the bitmap when you don't need it anymore (comment/uncomment to see the different result)
            //bitmap?.Dispose();
        }
    }
    if (!exceptionOccured)
    {
        MessageBox.Show("No exception after " + maxIterations.ToString() + " iterations");
    }
}

And the result (the bitmap was not disposed):

The same code, but disposing the bitmap in the finally block:

private void button1_Click(object sender, EventArgs e)
{
    int maxIterations = 5000;
    bool exceptionOccured = false;
    for (int i = 0; i < maxIterations; i++)
    {
        Bitmap bitmap = null;
        try
        {
            bitmap = new Bitmap(500, 500);
        }
        catch (Exception ex)
        {
            MessageBox.Show("Exception after " + i.ToString() + " iterations" + Environment.NewLine + ex.Message);
            exceptionOccured = true;
            break;
        }
        finally
        {
            //dispose the bitmap when you don't need it anymore (comment/uncomment to see the different result)
            bitmap?.Dispose();
        }
    }
    if (!exceptionOccured)
    {
        MessageBox.Show("No exception after " + maxIterations.ToString() + " iterations");
    }
}

And the result (the bitmap was disposed):