Photography: A Thousand Words

A Photographic History

A “pinhole camera” was discovered in approximately 400 BC, with by Aristotle and Mo Di. Subsequently, a “camera obscura” used this technology for light to enter and then project an image, which could then be used to draw images. Hundreds of years later, the discovery of silver nitrate by Magnus and silver chloride by Fabricius from the 12th and 16th century periods, along with the diaphragm discovered by Barbaro in the latter time period, allowed components that would come together with Homberg’s discovery of light-darkening chemicals to lead to the camera. Meanwhile, Wedgwood used a “dark room” for the painting technique using chemicals.

The year 1822 led to the initial “photoetching image” by Nicéphore Niépce on photographic plate – his original photo destroyed capturing nature, he made the now-oldest-surviving photograph “View of the Window at Le Gras” of nature. Because techniques then used engraving and the “camera obscura” or dark chamber (in Latin), exposure took a great deal of time. This was subsequently improved upon by Daguerre, who used silver halides which were sensitive to light and more defined by 1837. Interestingly, the first human photograph was taken in 1838 (who was a man who was having his shoes polished and had to stand still for 10 minutes due to the exposure time – hence, no street scenes of horse carriages/people moving/etc. were possible, due to the long exposure time needed.   Daguerre was offered a pension by France in exchange for the country to present his gift themselves to the world.

Separately in Brazil, Hercules Florence created a similar process called “Photographie,” while English inventor William Talbot created a process resulting in a “negative” which could be used to make multiple “positive” copies – this was created using the “calotype” type process he invented. In between 1819-1839, John Herschel created a “blueprint” and a “glass negative” – creating completely light-fast photographs. Natural-color photographs were invented based upon optical interference of light waves discovered by Gabriel Lippmann – for which he was awarded a Nobel Prize in 1908. While film was introduced in the 1890s, the cost and quality of glass being preferred by some led the latter still be used.

Light sensitivity work by Hurter and Driffield led to “film speed” being able to be measured, and with George Eastman marketing first flexible photographic roll made from flammable nitrocellulose, Kodak’s invention in 1908 known as “safety film” using cellulose acetate was less flammable.

Challenges with color photography included lack of “fixing” which resulted in fading; the first color photo in 1861 – physicist James Clark Maxwell used a 3-color separation technique with red, green, and blue fliters, which were superimposed and resulted in a color print. In 1907, the first commercially successful color process named “Autochrome” was invented by the Lumière brothers (using potato starch adding the colors). Kodachrome’s “integral tripack” combined red-, green-, and blue-only (RGB) components to create good color when complemented with cyan, magenta, and yellow (CMY). Emulsions helped develop the film. Polariod, an “instant” camera yielding an image in 2-3 minutes, was introduced in 1963.

In 1981, Sony introduced the Mavica which was the first “charge-coupled device” not requiring film, but displaying to television and saving to disk; Kodak DCS 100 was the first commercial digital camera – with an electronic image sensor.

 

Present Day Photography

Camera Function — Technical Aspects: A camera uses an image sensor to record the image – such a sensor may be a photographic plate, film or sensor. By controlling the camera and lens to expose light recording material to amount of light to form an image, such an action using electronic cameras include a charge-coupled device or complementary metal-oxide-semiconductor (CMOS) technology. Camera controls include:

  • focus (adjustment of the optical device to clarify an image);
  • aperture (f-number measuring lens opening with amount of light allowed – the higher the f number, the smaller the aperture and the greater the field depth – focal length/f-number = effective aperture diameter);
  • shutter speed – also a function of amount of time imaging medium is exposed to light – faster shutter speed decreases amount of light and makes images blurrier;
  • white balance – a method of calibrate colors being photographed to “true white” – this can be altered by calibrating to a different color, which may skew the appearance of other colors (to sometimes get a specific, desired effect);
  • ISO – an indicator of film speed in the past, it is now used for measuring gain for automatic exposure – the higher the ISO, the greater the film sensitivity to light (and vice versa);

Use of these techniques can result in unique images – for example, longer exposure times can result in tracking traffic as streams of lights or stars as similar streams in the sky. For objects in motion, a higher shutter speed is needed.

Photography and photographers can be categorized in different ways – some designate “amateur vs. professional” commonly.  There are many excellent amateur photographers who use the techniques above effectively, as well as professionals.  Professionally, and as with any artwork, “beauty is in the eye of the beholder” (as is value — with the highest price paid for a photograph as of March, 2015, is Cindy Sherman’s “Untitled #96” from 1981, selling for $3.89mm in 2011).

 

Future of Photography

Different photographic techniques that have been more futuristic but still already in use include stereoscopic (or 3-D, where side-by-side images emulating human stereoscopic vision are made), full-spectrum (in the infra-red, ultraviolet, and other non-visible forms of light or energy), as well as light field photography (which allows focusing at various depths in a digital image after taking a photograph; and photocopy (transferring electrical charges rather than photographic medium). Perhaps a bit removed by our dissociation, two areas of photographic advance continue to show otherwise difficult-to-visualize detail: (1) inner space using microscopy of various techniques, and (2) outer space telescopy/photographic image transmission. Considerations of each can contemplate what may be expected in the future:

  • Inner space – Photomicrography, a technique of photography via a microscope, is used in many ways, at different magnifications. Credited initially to Roman Vishniac who photographed “living creatures in full motion,” his initial efforts were later succeeded by others with electron micrography (prepared using the electron microscope). Based upon such techniques, structural and ultrastructural elements of a cell are able to be visualized, with amoeba, mitochondria, and snowflakes being examples of small images visualized by some of such techniques.
  • Outer space – Astrophotography, a technique of acquiring images of objects in outer space, is done using long exposure times, with the moon photographed in 1840 being the first such object, and subsequently in the late 1800s stars and nebulae, as well as other galaxies. Because of such a long time, the telescope itself had to rotate to compensate for relative movement of the earth. Some images, such as the first solar eclipse being filmed in 1851, were able to be captured quickly; Vega, the first non-sun star was captured by Bond and Whipple from Harvard College Observatory. Subsequent telescopes such as the segmented mirror telescopes, as well actual telescopes placed in space as the Hubble Space Telescope, have made significant advances. For example, the Hubble telescope is able to record stars 100 times dimmer than prior telescopes just 50 years prior.

As we realize that some of our spacecrafts are now at the reaches of our universe and proceeding beyond, images sent back in transmission could continue to give significant insight. Closer to earth, Mars exploration has already sent photographic images which suggest, along with other data, possible presence of forms of water.  Perhaps now, more than ever, the boundaries of outer and inner space, which are no longer visible to us with our naked eyes, are being made possible due to photography.

 

(Information above has been acquired from numerous sources, including www.inventors.about.com, www.khanacademy.org, www.pbs.org, www.wikipedia.org, and www.metmuseum.org, among others)

Ravish Patwardhan, MD