I'm just beginning to learn how to use SAGA 2.1.2 tools within QGIS 2.12.1 on a Windows 7 64 bit computer by working through exercises in Mastering QGIS by Menke et al. (https://www.packtpub.com/application-development/mastering-qgis). Chapter 7 introduces the SAGA raster calculator and "Clip Grid with Polygon" tool. In both cases we are to save the result as a .tiff file, but the only file type available in the "Save To" dialogue is .sdat.
Is there something wrong with my installation of SAGA (I've tried using both the stand alone QGIS Windows installer and the OsGeo installer), or am I missing something else? Mastering QGIS appears to have been written for an earlier version of SAGA, so the tool dialogues in the book don't quite match those in QGIS 2.12.
How can I save the output of these SAGA tools as .tiffs?