Short History of Photography

That Which We Obtain Too Cheaply, We Value Too Little

   1800 Tho's Wedgwood recorded images using Ag2NO3 on leather but could
        not preserve the images in light.

   1823 Nie'pce used AgCl on paper to record fixed scenes but long 
        exposures were not suitable for portrait photography.

   1827 Reasonably good photos are being made in Europe.
   1839 Daguerre and Nie'pce gave their processes to the French gov't
        in exchange for a good pension.  Exposures were down to 25 sec.
        by 1841.  The process spread worldwide.

        Plates, first manufactured by silversmiths in sizes that became
        internationally standard:

           Whole plate          165 x 216 mm        6.50 x 8.5  in.
           Half plate           114 x 140 mm        4.50 x 5.5  in.
           Quarter plate         83 x 108 mm        3.25 x 4.25 in.
           Sixth plate           70 x  83 mm        2.75 x 3.25 in.
           Ninth plate           51 x  64 mm        2.00 x 2.5  in.
        The daguerreotype is a silver-plated sheet of copper.  The silver
        side is polished and placed down on crystals of iodine where fumes
        make the light sensitive material silver iodide.  The plate is
        then exposed and passed over a vat of heated mercury where fumes
        form an amalgam with the silver producing an image.  A bath in a
        strong solution of sodium chloride renders insensitive to light
        any unexposed silver iodide.

   1840 Mar 04 1'st daguerreotype portrait gallery in NY
        By the end of 1840, 3 improvements increased the popularity of 
        daguerrotypes.  An improved lens designed by Josef Petzval, f3.6 
        transmitted 22 times as much light, and was distributed by Peter
        Freidrich Voigtlander of Vienna.  John Frederick Goddard used
        other halogens to increase sensitivity of the silver thereby
        speeding the exposures by accelerators or as daguerrotypists
        called it "quickstuff." Thirdly, Frenchman Hippolyte Louis Fizeau
        enriched the tones of the daguerrotype by adding gold to the
        silver increasing the dark tones and improving the mercury
        amalgam for brilliant whites.

   1841 Mar    1'st daguerreotype portrait gallery in Europe

   1841 Caleotypes become popular mostly in Europe.  Patented by Talbot
   1847 Albumen plates by Claude Felix Abel Niepce de St. Victor did not 
        last long.

   1850 Albumen paper became the most popular for prints.  Paper was
        coated with albumen mixed with potassium bromide and acetic acid,
        dried, floated on a silver nitrate solution and again dried.
        Pressed against a negative and exposed to bright sunlight, it was
        then toned in gold chloride, fixed in hypo, dried and sometimes
        pressed on a smooth drum for a glossy finish.

   1851 A new era opened with the invention of collodion by Frederick
        Scott Archer.  The process reigned supreme in photography until
        1880.  Collodion is a solution of nitrocellulose mixed with
        alcohol and ether.  Archer added potassium iodide to the mix and
        deposited the viscous solution on glass plates.  After dipping
        the coated plate in silver nitrate solution the "wet plate" had
        to be exposed, and developed in pyrogallic acid before drying.
        The collodion then dries becoming a tough waterproof film. Three
        collodion processes eventually displaced the daguerreotype.

   1854 Carte-de-visite photographic papers patented in France by Andre Adolphe-
        Eugene Disderi.  This was a collodion process.

   1854 Ambrotypes - a collodion process direct print, often having a glass
        plate cover attached by balsam.

   1855 Jun 01 Massachussetts records 403,626 daguerreotypes to that date.
   1856 Hamilton L. Smith assigns his patent for tintypes to William Neff &
        his son Peter.

   1864 few daguerreotypes in use.

   1866 New lenses Aplanat and Rapid Rectilinear markedly corrected for
        spherical abberation and astigmatism somewhat.