In addition to being the author of this excellent book, David Nightingale is responsible for the fabulous Chromasia (do a search) website. If you don't know his work, then do take a look and you'll see that his credentials as a wonderful photographer are never in doubt. He also writes very well explaining sometimes complex concepts clearly and concisely. Naturally, this book is written in similar style. It's easy to understand and explains simply how to achieve the "extreme" techniques of the title. The photographs used, many his own, are terrific and the book is beautifully produced. Highly recommended.