Secret Knowledge by artist-turned-writer David Hockney has created quite a stir in the art world. His book was featured on 60 Minutes -- that’s how controversial it is. What’s the fuss? Turns out that Hockney has a theory that many of the old masters (Caravaggio, Vermeer, Hals, etc.) used lens and mirrors to create their masterpieces. In simple turns, the artist projected the sitter’s image onto a canvass and – dare I say it? – traced the image! A collective gasp was heard among art historians and museum curators the world over. The question remains: Is Hockney right? You be the judge. In this lovely book, worthy of any coffee table, Hockney provides pages upon pages of visual evidence. He meticulously tries out his theory by examining major artworks, dissecting their composition, lighting, angles, and then shows us why he suspects the masters had more than oil paint and a brush up their sleeves.

The device that helped painters create photographic likenesses of their sitters was the camera obscura. What led Hockney to presume painters kept a scientific secret for over 400 years? While sitting and gazing at a series of portraits that spanned 200 years, he marveled at the realism that sprung spontaneously in the late 1400s and ended soon after the invention of the Daguerrotype (the granddaddy of photographs). He then compared international portraits spanning a 400-year period and noticed that the similarities in technique spread from Italy to the Netherlands. Hockney compares a set of Durer portraits, one prior to his visit to Italy, one post. If a picture really is worth a thousand words, he makes his point. It is hard to dispute the visual evidence he provides. Hockney points out that the invention of the camera and popularity of photography created a new movement – impressionism and cubism – artists no longer needed to produce realistic portraits and began to experiment.

I still don’t understand why this book raised such a hew and cry in the art world. The use of the camera obscura, or camera lucida, does not detract from the magnificence of the artwork; it does not dull the shine of the satin robes in a Frans Hals painting. Originally, critics accused Hockney of trying to place masterpieces in the category of the “paint-by-number set.” I have painted many a paint-by-numbers in my day, and none of them looked like a Diego Velazquez. Talent is talent, no matter what method was used to bring these gorgeous works to life.

Will reading this book destroy or enhance your appreciation of the great masters? No. I spent many hours in the Louvre admiring the Flemish painters; my eyes teared up beholding such beauty, and now Hockney has shown me a new way of seeing. I appreciate these works even more – however, I do notice the quirkiness of disproportionate limbs to heads. To quote John Singer Sargent, “A portrait is a painting with something wrong with the mouth.” The images included in the book are well worth the price – and if you like gossipy letters, you will love the inclusion of Hockney’s correspondence with art historians, painters, and friends as he works his way through his art theory. If you love art, a good mystery, and a chance to compare centuries of masterworks, you’ll love this book. No illusion, this is five out of five stars.