Cameras, Automatic. History of Evolution

The quality and precision of a photograph is basically dependent on the aperture, the light sensitivity of the film, and the shutter speed of the camera. As photography became a sought-after source of record keeping for the amateur, demand increased for a camera that could automatically align this seemingly nefarious collaboration of technical details. The evolution of the automatic camera inevitably reflects the mechanical, electronic, and high-tech progress of the twentieth century, but primarily employed its own specific mechanical innovations.

Prior to the twentieth century, cameras were a fairly cumbersome collection of enormous photographic plates and large boxes, usually mounted on massive tripods in order to keep camera perfectly steady for an image to burn the film without blurring. In the 1870s faster-exposure plates were introduced and the shutters that controlled light exposure were built for the first time inside the camera, reducing some of the bulk.

By the turn of the century a wide variety of cameras were available for every special purpose imaginable, including gigantic cameras that produced large prints and double-lensed ‘‘stereo’’ cameras that created three-dimensional and panoramic images. But the amateur photographer was left out of these innovations, too inconvenienced to master the complicated equipment and heavy, expensive photographic plates.

In 1888, American George Eastman brought ‘‘Kodak No. 1’’ to market, as the first hand-held camera, which used rolls of film in place of the photographic plate. While this ‘‘snapshot’’ camera was quite popular, quality photographs from a hand-held camera that could manipulate the necessary components—aperture, shutter speed, and film speed—were decades away. The Kodak No. 1 was set at a single speed shutter of 1/25 of a second, and it used a fixed-focus lens good for any subject more than 2.5 meters away. The camera came preloaded with a roll of 100 pictures, which the photographer had to send, along with the camera, back to Kodak to have developed and reloaded.

It wasn’t until 1925, at the Leipzig Fair, that German E. Leitz introduced the Leica camera, which used a higher-quality 35 mm film, a fast focal-plane shutter, and a more precise f/3.5 lens. These adaptations created a camera that could take high-quality photographs under a variety of conditions. The focal plane shutter could give a range of exposures, from 1/1000 second to 1 second, and the lever that operated this mechanism also advanced the film.

The lens, which was fast enough to allow for indoor photography, was also connected to a rangefinder that focused easily at the hand of the photographer. The Leica ushered in a new era of photographic conveniences, and soon photojournalism became a fixed—and critical— customer of these new hand-held cameras.

Soon thereafter, the growing needs of photojournalists and discriminating amateur photographers inspired the creation of similar handheld cameras with slight improvements over the Leica. In 1927, Rolleiflex introduced the twin-lens reflex camera, employing a separate focus lens through which the photographer looked, and a parallel lens that captured the image. Ten years later, a singlelens reflex (SLR) hand-held called the Exacta came to market, which allowed the photographer to easily focus through one 35 mm lens.

The shutter of the first SLR cameras was dependent on a fast- moving slit that exposed different parts of the subject at different times across the film, distorting fast-moving objects. But the technology of the SLR cameras eliminated the parallax error—or the difference between the image that goes through the lens and the image seen through the viewfinder—of the smaller viewfinder cameras. Using a mirror and a diaphragm, the SLR camera allows the photographer to both compose the image and focus through the 35 mm lens.

Following these improvements, a series of cameras that appealed to the novice photographer came on the market. Most notably, American Edwin H. Land created a camera that used a film capable of producing developed shots on demand—the precursor to the Polaroid camera. After World War II, a sudden plethora of camera manufacturers produced cameras that used 110 film and electronic controls, taking Eastman’s snapshot Kodak No. 1 a step further by allowing a slight range of shutter speed, but still employing the same basic fixed-focus lens.

Lens and optical companies soon designed their own versions of the Kodak and Leica amateur- friendly cameras. By 1946, Japanese companies developed 35 mm cameras. All these cameras still required imprecise threading of film, manual control over focus, aperture and shutter speed. The next step in improvements came in the form of film rolls that snapped into a fitted compartment and threaded themselves.

Eventually, automatic control over exposure was also incorporated, using a built- in light meter that reads the level of illumination, then sets either the aperture, or shutter speed, or both together. In general, these two forms—the leaf shutter and the focal-plane shutter—are still used today. Originally in Leicas’s historical camera, the leaf shutter consists of a series of overlapping blades in the lens, powered by a spring-loaded shutter button. When the shutter is pressed, the blades open and shut according to the settings.

The focal-plane shutter, on the other hand, is not in the lens but the camera itself, directly in front of the film. It is a faster mechanism, allowing for faster exposure, utilizing two curtains that open slightly— also by a spring-driven shutter button—exposing the film to a window of light.

Automation of shutter speed and aperture accompanied the development of the built-in exposure meter. This is done by ‘‘reading’’ the light reflected from the object being photographed by a needle in the light-measuring device. The needle measures the light, moving into position. When the shutter button is released, the needle becomes fixed, and a scanner arm moves until it hits the needle. The end of the scanner arm then engages the devices that control the shutter and the aperture diaphragm.

By the late 1950s, camera companies included extras like timers, and by the late 1960s, Polaroid created the first color instant film and the first ‘‘instamatic’’ camera, which was similar to the 110- film cameras of the forties, but with color film.

Autofocus, present in the 1950s in its most basic form, utilized a motor that spun the lens’s focus ring, which was usually inside the lens. Over time, manufacturers built the motor in the body of the camera, but the poor quality of these early systems earned autofocus a bad reputation (especially among expert photographers).

By the 1970s, however, the American-company Honeywell earned a patent for phase-detection autofocus, which was applied to Konica’s C35 AF camera. Basically, the system works by taking light from the subject that passes through the lens and the semitransparent reflex mirror. Another mirror directs the light toward the autofocus module, and an array of light-sensitive charge-coupled devices, or CCDs. The distance between the CCDs determines the focality of the image. A small circuit board then controls a motor that moves the focusing ring of the lens.

By the 1980s, compact, ‘‘pocket-sized’’ 35 mm cameras with autofocus came onto the market, employing systems developed mostly by Japanese manufacturers, who fine-tuned the Honeywell technology and added computer technology and microelectronics to the mechanism controlling the systems. In addition, the perils of setting aperture and shutter speed were further relieved by a new kind of light meter employing a panel of semiconductor sensors that translate the light level into electrical energy. The light meter then ‘‘reads’’ the film speed by special markings on the outside of the 35 mm cartridge and accounts for shutter speed to adjust for the correct aperture.

By the early 1990s, both automatic focus and light meters required nothing of the shooter. Central microprocessors, now fairly common in cameras, activate several motors that control focus, shutter speed and aperture, in a single click. Automatic cameras at the beginning of the 21st century are closer to computers, especially as digital cameras have become a standard piece of equipment for the amateur.