When I wrote the first edition of this book, I said that the time was not yet ripe for a comprehensive handbook of DSLR astrophotography. Now it is, and I have rewritten almost the entire book from scratch because so much has changed and so much more knowledge is available. And the torrent of new developments never stops. Please check this book’s web site, www.dslrbook.com, for updates and additional information immediately. Not everyone will read all the chapters of the book straight through. To cover such a complicated, technical subject, I have had to spiral outward through the subject matter, passing through several regions more than once.