A different light on digital photography

If you want to learn about digital photography but have had your fill of redeye reduction tips and unsharp mask tutorials, a new book by Stephen Johnson is worth a look. On Digital Photography (O'Reilly 2006, $40) has plenty of pointers on color correction and tonal balance, but what sets it apart is Johnson's enthusiasm for the history and mechanics of digital photography--and the abundant landscape pictures that serve as inspiration.

Johnson's perspective has the benefit of history--he's been guiding Adobe on Photoshop since the product's inception and has been deeply immersed in digital imagery since the days when that meant scanning film. And he's paid his pioneer dues: in a 1994 project to digitally photograph U.S. national parks, he'd have to stay awake into the wee hours offloading images from his camera's hard drive onto tape so he'd have room for the next day's shots.

On Digital Photography isn't for the casual snapshotter.

Johnson's guidance tends toward higher-end matters such as duotones, histograms, archiving, high-dynamic-range images and color-space considerations of printing. When it comes to the book's practical advice, the ideal audience are people who devote a lot of time and money to photography. Even then, exercise caution: some sections of the book are relatively timeless, but others involving fast-moving technology, such as image repair or raw image processing, are in danger of being rapidly dated.

For those who want to dig into the details of the technology, Johnson provides plenty of material. He details the inner workings of camera image sensors, illustrates the differences in how many shades of gray can be displayed with 8-bit, 12-bit and 16-bit image data, explains image conversion between two color spaces, and shows historical digital sensors used in spy satellites and interplanetary probes.

The book is stocked with numerous reproductions of Johnson's own photographs, a delight to behold and ample incentive to head out with your own camera. My favorites are images that at first blush appear washed-out or overexposed, but on deeper inspection are a true reflection of their subjects.

Be inspired, but don't get your hopes up too high, though: Johnson not only is more skilled, disciplined and patient than most of us, but most of his shots are taken using BetterLight imaging equipment that costs between $7,000 and $18,000--not including lenses or even the camera body. Indeed, the book is something of an advertisement for the technology.

On Digital Photography is a somewhat meandering exploration of what's on Johnson's mind. It also includes some previously published material, not so fresh but still valuable. Overall, Johnson's tour of the digital photography landscape, while not terribly structured, is one worth taking.