The scripts below show how to convert PDF to multi-page TIFF image in C# and Visual Basic .NET using Bytescout PDF Renderer SDK.
C#

using Bytescout.PDFRenderer;

namespace PDF2TIFF
{
	class Program
	{
		static void Main()
		{
			// Create Bytescout.PDFRenderer.RasterRenderer object instance and register it.
			RasterRenderer renderer = new RasterRenderer();
			renderer.RegistrationName = "demo";
			renderer.RegistrationKey = "demo";

			// Load PDF document.
			renderer.LoadDocumentFromFile("multipage.pdf");

			int startPage = 0;
			int endPage = renderer.GetPageCount() - 1;

			// Save PDF document to black-and-white multi-page TIFF at 120 DPI
            RenderingOptions renderingOptions = new RenderingOptions();
            renderingOptions.TIFFCompression = TIFFCompression.CCITT4;
            renderer.SaveMultipageTiff("multipage.tiff", startPage, endPage, 120, renderingOptions);

			// Open the first output file in default image viewer.
			System.Diagnostics.Process.Start("multipage.tiff");
		}
	}
}

VB.NET

Imports Bytescout.PDFRenderer


Class Program
	Friend Shared Sub Main(args As String())

        ' Create an instance of Bytescout.PDFRenderer.RasterRenderer object and register it.
		Dim renderer As New RasterRenderer()
		renderer.RegistrationName = "demo"
		renderer.RegistrationKey = "demo"

		' Load PDF document.
        renderer.LoadDocumentFromFile("multipage.pdf")

        ' define page to start from
        Dim startPage As Integer = 0
        ' define page to end on
        Dim endPage As Integer = renderer.GetPageCount() - 1

        ' Save PDF document to black-and-white multi-page TIFF at 120 DPI
        Dim renderingOptions As New RenderingOptions()
        renderingOptions.TIFFCompression = TIFFCompression.CCITT4
        renderer.SaveMultipageTiff("multipage.tiff", startPage, endPage, 120, renderingOptions)

        ' Open the first output file in default image viewer.
        System.Diagnostics.Process.Start("multipage.tiff")
	End Sub
End Class