|A pinhole camera has no lens. In its place is a an extremely
small aperture (f/138 for the Zero Image Pinhole's) through which exterior
light is projected onto sensitive film or paper. A lens functions by collecting
the light rays outside, inverting them, and focusing them into a smaller
image. A pinhole does not focus at all. It merely acts as a "center
of projection" inverting the light rays without re-organizing them.
The size of the inverted image depends on the distance of the pinhole to
the projection surface - a closer distance yields a smaller image and vice-versa.
As the hole is not truly a point, it allows more than only one ray from
the subject to register on the film. This imparts a characteristic "soft
focus" effect. Moreover, as the light is not altered, the pinhole has
nearly unlimited depth of field, with reasonably close objects registering
at the same sharpness as far away objects (okay, REALLY close objects will
be blurred!). As the pinhole is so tiny, it yields a wide-angle focal view
and reproduces true geometrical lines, unlike the usual curved effect
of a wide-angle lens. It also requires a fairly long exposure time - about
2 seconds in bright sunlight!
The science of Pinhole optics goes back a ways. Although its exact origins are debated, the basic principles are widely credited to China in the 5th century BC. According to several sources, the philosopher Mo Ti was the first to record the formation of an inverted image through a pinhole. Much later, in the 10th century AD and across the world, an Arabian mathematician Ibn Al-Haitam made his own discoveries - that light moves in linear waves and can be projected through small holes. Very nice. Now, fast forward to the European Renaissance, when pinhole truly started to come into its own. Our friend Leonardo DaVinci describes pinhole image formation in his hard-core Codex Atlanticus. In 1580, the Roman papal astronomers used a pinhole-powered observatory to create the newly correct Gregorian calendar. Around the same time, the term "camera obscura" ("dark box") was coined by Johannes Kepler in Austria, and used to describe a room or box with a lens aperture that served to project an outside image onto a wall. Herr Kepler went on to create a portable camera obscura in 1620, a crude predecessor to the more intricate pinhole devices to come.
Sir David Brewster, a scientist from bonnie Scotland, was the first to create a proper Pinhole photograph. He began shooting madly in the early 1850's, and is also credited with coining the actual phrase "pin-hole." For you 3D-heads out there, you can also thank Sir Brewster for the creation of the modern Stereoscope camera. Following these heady days came a swarm of pinhole sensations - Flinders Petrie's Egyptian archeological shots in the 1880's, a wave of Impressionist-style shootings the world over throughout the late 1890's and early 1900's, the introduction of the truly commercial Kodak Pinhole camera in the 1960's, and retro-style artistic musings throughout the 1970's and 1980's. Which brings us to today. In the era of megapixels, autofocus, and Photoshop, the pinhole camera holds more charm than ever. It's sheer simplicity is actually thrilling, and even a little awkward as first you manipulate this completely silent camera and wonder if the shots will actually come out. Yet, out they come! The real excitement comes at the development desk, as you're awed with the incredible, jewel-like and often unpredictably beautiful images that result. Break from the surgical perfection of ultra-techno photography. Embrace the pinhole's no-viewfinder, no-exposure, barely-a-shutter, did-it-actually-work? techniques. Get in touch with the very roots of photography, and be rewarded with images that look as fresh and dazzling as ever.