Read an Excerpt
By Neil deGrasse Tyson
In astrophotography, unlike all other branches of this noble art, the cosmic photographer does not get to illuminate the subject or tell the subject to stand a different way to improve the angle of view. The sky above is just "there." The objects in it are just "there." Not only that, the extreme light travel time from the depths of the universe to Earth forces the photographer to view most objects not as they are but as they once were, long ago. Beyond these profound limitations, one might be further surprised to learn that the most interesting objects in the universe are so dim that the photographer does not even see in advance what the picture will become when fully exposed. Astrophotography might then be the humblest of hobbies, even while its subject draws from the most beautiful vistas there ever were.
In modern times we have no shortage of beautiful cosmic images from celebrated professional sources, such as the Hubble Space Telescope. So why turn to an atlas chock full of images taken not just by professionals, but by amateur astronomers with their personal cameras from their suburban backyards? First, the era of affordable digital detectors greatly reduces the relative advantage that a professional telescope formerly had over amateur equipment. Second, the field of view of professional telescopes is generally quite small. The Hubble, for example, sees no more of the night sky than 1/100 the area of the full moon. Meanwhile, an amateur setup using a simple camera, or a camera combined with a moderate-size telescope, can capture large swaths of sky-in some cases, entire constellations-revealing dim but large-scalefeatures within our own Milky Way that would otherwise lay undiscovered in front of our noses.
As we have known for some time, Earth rotates continuously. As these large-scale features drift by, any attempt to expose an image for more than a few seconds blurs the stars and other light-emitting objects, just as would a time lapse of car headlights along a highway. To avoid this, one must somehow compensate precisely for Earth rotation. Of course, the clock drive was invented long ago to solve just this problem. Some clock drives even allow you to make adjustments to follow objects, such as comets, that are themselves in motion against the drifting background sky. In all cases, the sharpness of a final image depends heavily on how well the clock drive works, especially for the longest of exposures one may require.
The camera and telescope combo operates like a light bucket. In a fraction-of-a-second exposure, such as what the brain does with human vision, you can detect only so much light. But with full control over exposure time, combined with the highly sensitive digital detectors used in modern cameras, you can fill your bucket with as much light as you like-exposing the scene for as long as you have the patience to support and as long as you trust the stability of your clock drive. A single image can take several minutes to expose. Others can take several hours; still others, the most challenging targets of the night sky, may require many nights of work.
With each added moment of exposure, the gossamer, ghostlike features of a nebula or a galaxy become brighter, more delineated, more revealed. Like the sculptor in Pygmalion, where each strike of the hammer and chisel brings the subject closer and closer to life, the astrophotographer exposes the detector until the subject rises from the depths of space to become a work of art unto itself. And whether or not the nebula or galaxy comes to life, what's certain is that, as in Pygmalion, the astrophotographer falls in love with the images themselves.
In this case, Robert Gendler's Astrophotography by the Masters cannot be read and viewed without feeling that these committed photographers are smitten by the universe and hopelessly enchanted by the objects it contains, while inviting the reader to be similarly taken by their splendor.
Neil deGrasse Tyson, though a professional astrophysicist for more than two decades, continues to count himself among the ranks of amateur astronomers-an association he has held since the age of twelve, when he took his first photographs of the night sky. Tyson is director of New York City's Hayden Planetarium at the American Museum of Natural History and is the author of nine books on the universe, most recently Death by Black Hole: And Other Cosmic Quandaries and The Pluto Files: The Rise and Fall of America's Favorite Planet.
The core of this book relates to astrophotographers and their art. The essence of this photographic compilation is to bring to print the most provocative and visually compelling portraits of the deep sky and of local astronomical phenomenon taken by the world's most accomplished astrophotographers. The modern astrophotographic process can be broken down into the technical and the artistic. The technical aspect is substantial and requires technical precision and refinement of the highest order. It is beyond the scope of this book to list the numerous technical innovators who were so vital to establishing the enormously sophisticated state of modern astronomical imaging that we enjoy today. That said, in a few cases the successful practitioners and technical innovators were one and the same.
Capturing the Stars pays homage to the most accomplished practitioners of the art of astronomical imaging-professional and amateur, past and present-who have produced the most stunning, creative, and significant astronomical images of their time. The book features thirty-five astrophotographers from fourteen countries, a testament to the degree of international participation in astrophotography today. The one common thread among them is an obsession with recording phenomena of the night sky and a great joy in sharing their passion and spectacular results with the rest of the world. When passion exists, it often compels people to do extraordinary things. The astrophotographic masterpieces in the following anthology of have already been recognized as extraordinary, but the images have not yet appeared together under the same cover until now. They were produced by an elite group of dedicated and talented people from around the world who have established original techniques, styles, and directions in astrophotography and who have set the standard for astronomical imaging in their time. The results of their dedication, creativity, and untiring labor reveals itself in the pages ahead.
Soon after the announcement of the first photograph in 1839 by Louis Daguerre, a camera was turned towards the moon and, with the awkward snap of a primitive shutter, heralded the age of astrophotography. Photographs of the sun, planets, stars, and comets soon followed. The first long-exposure photograph of a deep-sky object-the Orion Nebula-was recorded in a fifty-one minute exposure by Henry Draper in September 1880. It was followed by a photograph of the Andromeda galaxy in 1884, taken by A. A. Common. In 1923, in one of the great milestones of astrophotography, Edwin Hubble made history by resolving stars in the Andromeda Galaxy using the 100-inch Hooker Telescope at Mount Wilson Observatory in California. This event defined the beginning of modern cosmology: Galaxies were now recognized as individual island universes receding from each other, formed from a common beginning.
Over the next century, innovations were directed at overcoming the chief limitation of film, known as reciprocity failure, which imposed serious limitations on recording faint celestial objects. Various techniques such as heating, cooling, baking, and, later, gas hypersensitization all achieved partial success in making film more suitable for deep-space astrophotography. In 1969, the world of astrophotography underwent an extraordinary revolution when Willard Boyle and George E. Smith of Bell Labs used a charge-coupled device to record images electronically. The charge-coupled device (CCD), a linear recorder of light, overcame the problem of reciprocity failure and propelled astrophotography into the modern age.
A series of technical advances during the next few decades transformed the early CCDs from primitive devices into highly efficient, low-noise, large-format light detectors capable of pushing the limits of depth, detail, and color, well beyond what was possible with film. Joined to modern telescope designs, the CCD has produced astounding cosmic images along with an explosion of new knowledge and astronomical discoveries.
The transformation of astrophotography from a technical craft to a photographic art form began only recently. For more than a century after its inception, astronomical imaging remained exclusively a technical exercise. The astrophotographer was considered a skilled technician, at most an "artisan," whose photographs made possible advancements in the science of astronomy. Between the late 1940s and the 1960s, astrophotography remained within the domain of large professional observatories, particularly the renowned Mount Wilson and Palomar observatories, whose sky surveys produced many of the most famous and inspiring astrophotographs of that era. William C. Miller produced the first color-corrected astrophotograph in 1958, but it wasn't until David Malin's work in the 1970s and '80s, at the Anglo-Australian observatory, that color astrophotography came into its own. Malin's monumental tricolor film images established astronomical photography as not only a tool of science but as "works of photographic art."
Although amateurs had always played an important role in advancing astrophotography, it is only within the last two decades that high-precision telescope and imaging equipment have become available to nonprofessionals as "off the shelf" products. Finally, a remarkable craft was accessible to those enthusiasts eager to pursue astrophotography for nothing other than pleasure. In the hands of these "amateurs," astrophotography flourished and matured. Although accepted for some time in the realm of traditional photography, the concepts of creativity and personal expression were embraced only gradually and cautiously in the world of astrophotography. Following the digital revolution, imagers increasingly adopted key concepts from traditional photography, such as composition and elements of visual impact. They integrated these traditional ideas with newer techniques for the enhancement and manipulation of light and color, ultimately applying them in new ways to produce works of extraordinary visual impact and refreshing creativity. Over time, many amateur astrophotographers began to establish their own personal styles. The last decade, in particular, has witnessed a defining transformation in the field of astrophotography. Once an arcane cousin of traditional photography, astrophotography has arrived as a valid and worthy art form in its own right. With this transformation, the term "astrophotographer" has been redefined: The "artisan" of photographic astronomy is now the "artist" of the night sky.
Astrophotography serves both art and science. The rewards are profound and exhilarating; however, the rigor of astrophotography is less well known. Over the years, the difficulties have shifted from one aspect of the process to another. Early on it was the maddening task of guiding the telescope by hand for hours on end while trying to expose an image. Early astrophotography was essentially an endurance sport that tested the limits of concentration and sleep deprivation. The photographers were often stationed outdoors, exposed to the elements, and pushed to their physical limits. Some have claimed that this practice shortened the life of the pioneer astrophotographer Edward Barnard. Later, the emphasis shifted to darkroom wizardry with the astrophotographers' time and effort focused on the task of extracting information buried within photographic emulsions. In today's electronic imaging age, the challenges have shifted once again and are now directed at mastering the myriad software tools required to extract data from millions of tiny pixels that compose the large CCD arrays in use today. The development and mastery of digital enhancement methods has lifted astrophotography into a new era, taking it to astonishing degrees of depth, detail, and color and creating endless opportunities for creativity and visual impact.
Times and techniques have surely changed, but in a fundamental sense, the essence of astrophotography has remained pure. From glass plates to film to silicon detectors, the dream of the astrophotographer has always been the same: to capture and share a moment of exalted natural beauty and to learn through imagery the truth about our cosmic world. These scenes, which we are unable to behold with our own eyes, are brought to life through the marvels of astrophotography.