When I wrote the first edition of this book barely a handful of amateur astronomers were using electronic means to capture and store astronomical images. How things have changed in just a few years! While it is true that the practitioners of electronic imaging are still in the minority of amateur astronomers, certainly the rapidly growing numbers demand that the former brief notes be expanded into a full chapter for this edition.

If it is really true that ‘the difference between men and boys is merely the price of their toys’, then I think this distinction is equally applicable between amateur and professional astronomers. Amateurs had to wait until the required equipment became available at affordable prices before they also could begin to exploit the powerful advantages of electronic techniques newly enjoyed by the professionals.

Even so, the equipment is still relatively expensive and the techniques necessary to do what the professionals can do are somewhat involved. If you think ‘why bother?’, then the answer is given by the results achievable. Your backyard telescope can be transformed into a powerful research tool capable of producing results to rival those obtained with the large mountaintop observatory telescopes, when they used to record on the photographic plates of yesteryear.

I have just said that the equipment is expensive and the techniques a little involved. Throughout this book I try to provide simple and cheaper alternative ways of doing things wherever possible.