public partial class MainForm : Telerik.WinControls.UI.RadForm
    {
        public MainForm()
        {
            InitializeComponent();
        } 
        private void radButton1_Click(object sender, EventArgs e)
        {
            using (CameraForm f = new CameraForm())
            {
                f.ShowDialog();
            }
        }
    }

    public partial class CameraForm : Telerik.WinControls.UI.RadForm
    {
        public CameraForm()
        {
            InitializeComponent();
            
        }

        private void CameraForm_FormClosing(object sender, FormClosingEventArgs e)
        {
         this.radWebCam1.Stop();           
        }

        private void CameraForm_Load(object sender, EventArgs e)
        {

            ReadOnlyCollection<MediaFoundationDeviceInfo> videoDevices = RadWebCam.GetVideoCaptureDevices();
            ReadOnlyCollection<MediaFoundationVideoFormatInfo> videoFormats = RadWebCam.GetVideoFormats(videoDevices[0], true);
            radWebCam1.Initialize(videoDevices[0], videoFormats[0]);
            radWebCam1.Start();
        }
    }