Presentation on theme: "History of Photography Astronomical Photography Mary Kay Hemenway With materials from McCormick Observatory and other sources."— Presentation transcript:
History of Photography Astronomical Photography Mary Kay Hemenway With materials from McCormick Observatory and other sources
Niépce and Daguerre In 1824 Joseph "Nicéphore" Niépce (at left; ) created the first semi- permanent images using glass plates coated with a dispersion of silver salts in bitumen. In the early 1830's Niépce's partner, Louis Jacques Mandé Daguerre (at right; ) accidently discovered a method for creating a permanent image on a photographic plate, which was simply a thin film of polished silver on a copper base, sensitized by exposing the silver face to iodine vapors to form a thin yellow layer of silver iodide on the surface of the silver.
Niépce's View from the Window at Le Gras. c Gernsheim Collection Harry Ransom Center / University of Texas
Chemical details Development: expose the plate to a current of magnesium vapor heated to a temperature of 75° Celsius. The vapor would adhere to the part of the plate which had been exposed to the light. Fixing: immerse it into sodium thiosulfate, which was used to dissolve the unused silver iodide Rinsing: rinse in hot water to remove any remaining chemicals.
Photogenic drawing 1834, William Henry Fox Talbot ( ) Coat drawing paper with salt solution After it dries, add a solution of silver nitrate. Place a leaf, or fern, or a piece of lace, on the paper's surface and expose it to the sun. Result: an image National Trust
Photographic Negative August 1835, Talbot made the earliest known surviving photographic negative using a camera, a small photogenic drawing of the latticed window in the south gallery of Lacock Abbey. Source: William Henry Fox Talbot: [The Oriel Window, South Gallery, Lacock Abbey] ( ) | Heilbrunn Timeline of Art History | The Metropolitan Museum of Art Later image of Lacock Abbey window 3 1/4 x 4 3/16 in. (8.3 x 10.7 cm), irregular
John Frederick Herschel ( ) Fix images using hyposulphite of soda in 1839 (found the hypo could dissolve salts 20 yrs earlier) paper entitled "Note on the art of Photography, or The Application of the Chemical Rays of Light to the Purpose of Pictorial Representation," presented to the Royal Society on 14 March He coined the terms “photography’, "negative" and “positive" in this context, and also the "snap-shot". Images are Herschel by Julia Cameron ( ) and Hershel’s 1839 image of his father’s telescope (first image taken on glass)
First astronomical photos 1 st daguerrotype of the moon by American physiologist and chemist John William Draper ( ) in 1840, 20 minute exposure (later destroyed by fire). Solar spectrum 1840, John Draper
Stars, planets, and moon The first star was not recorded until the night of July 16-17, 1850, when William Cranch Bond, the director of Harvard College Observatory, and J. A. Whipple, a photographer associated with Massachusetts General Hospital, took a daguerrotype of Vega. At right is an 1852 daguerrotype of the Moon taken by Whipple.William Cranch BondHarvard College Observatory
Need for faster Process Astronomers needed a method to produce better quality images in less time. In 1851, Frederick Scott-Archer ( ) published an article describing the wet collodion process, although Gustave le Gray ( ) and Robert J. Bingham ( ) earlier had suggested and experimented with the technique. higher sensitivity than the early daguerrotypes, but it needed to be used as soon as it was made.
Wet Collodion Process: Chemical details Sulfuric acid and potassium nitrate were reacted on a small quantity of cotton to create guncotton (nitrocellulose). This guncotton was dissolved in alcohol and ether with iodides and bromides of cadmium, potassium, and ammonium. The resulting colloid was spread on glass plates and evaporated to leave a thin film of nitrocellulose impregnated with bromides and iodides.
Wet Collodion Process When the plates were dry, they were dipped into silver nitrate which was saturated with silver iodide, and this transformed the iodide and bromide into salts of silver. This silver halide coating was sensitive to light, but the plate had to be used immediately, or else the silver nitrate would crystallize.
Wet Collodion Process picture credits: PBS and After the image was taken, the plate was developed in a bath of iron sulfate, acetic acid, and alcohol which turned the exposed silver halide grains into metallic silver. Sodium thiosulfate was used as a fixer to remove the remaining (unexposed) silver halide grains the plate was then washed to remove the chemicals a coat of varnish was applied to protect the image.
An example Mizar and Alcor were photographed in March 1857 at Harvard College Observatory on wet collodion. The 1874 transit of Venus was also widely photographed on collodion plates as well as daguerrotypes. The collodion plate at right was taken in Japan by Jules Janssen ( ), later director of the Meudon Observatory.
Technological breakthroughs in 1870s 1871, Richard Leach Maddox ( ) - the first positive dry emulsion for physical development, using gelatin (a transparent animal protein) 1874, J. Johnston and W. B. Bolton made the first negative emulsion for chemical development 1878, Charles Bennett had discovered a method by which he could increase the speed (sensitivity to light) of gelatin-silver bromide emulsions by aging them at 32°C in a neutral medium. 1879, George Eastman ( ) invented a machine to coat plates with emulsion, so that the plates could be produced in mass numbers, relatively quickly and cheaply. Maddox
Astronomy advances With silver bromide dry emulsion plates, the first good photographs of Jupiter and Saturn were made in , and of comets in 1881 (Tebbutt's comet). A 51 minute exposure of the Orion Nebula was taken in September 1880 by Henry Draper ( ) 1882, Draper took 137 minute exposure which revealed the entire nebula and the faintest stars in it. 1872, the first spectrum of a star- Vega-was taken by Henry Draper.
1880 photo 1882 photo
Astronomy advances 1882 Sir William Huggins (who was the first to show that stellar spectral lines could be identified with terrestrial elements, in 1864) took the first spectrum of a nebula (the Orion Nebula) 1899 the first spectrum of a "spiral nebula - 7½ hour exposure -taken by Julius Scheiner ( ) with the Große Refractor of the Astrophysical Institute of Potsdam Observatory : The first sky surveys were done at Harvard, each photograph covering a 15°x15° area of the sky and reaching stars as faint 8th magnitude. Scheiner
Emulsion Grain Size The first emulsions had grain sizes of about 10 micrometer in diameter. Today, emulsions generally have grain sizes about ten times smaller than the earliest ones, or about one micrometer, and this allows for much more detailed photographs to be taken.
Color Sensitivity Hermann Wilhelm Vogel ( ), working in Berlin in 1873, accidentally discovered a way to make photographic emulsions sensitive to colors of light other than blue. At the time, green dye was used to soak up reflections off the back side of the glass in a photographic plate. Sometimes this green dye got into the emulsion along the plate edges, and Vogel noticed that the plate in this area was more sensitive to light of a longer wavelength or redder color. By 1874 Sir William de Wiveleslie Abney ( ) was able to put together an entire optical solar spectrum, from violet to infrared. Early 20 th century, C. E. Kenneth Mees ( ) at Eastman-Kodak made outstanding improvements in emulsions and spectral sensitivity. Kodak provided plates at cost to observatories.
Hypersensitization For very faint objects the emulsions react differently with light which has come in at a quick rate versus light which slowly filters in. This phenomenon is known as reciprocity failure. The first person to determine a way to partially overcome this problem was Fox Talbot ( ) in 1843, who discovered that heating emulsions prior to exposing them increased their efficiency for short exposures. 50 years later, William Abney and King found that chilling emulsions made them more efficient for long exposures. Among hypersensitizing techniques are water bathing, pre-exposure, ammoniating, mercury- vapor treatment, and high temperature baking for several different emulsions. Talbot Eastman