I bought this book a few weeks ago to give me a better insight into the use of filters with digital photography.
The book is very informative and is based in two sections. The first section deals with filters such as ND filters, Polarizing filters, Close up filters etc; The information was invaluable to assisting in obtaining better photographs.
The second section deals with computer filtration with photoshop etc; This again was a very infromative section.
At the end of the book there's a useful section on web sites for camera products and what companies specialize in what goods.
Overall a very good book that I will often refer to for assistance.
Well worth the money.