WET COLLODION PROCESS

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Survey of Negative Processes Glass-Based Processes


Contents

[edit] historical background

  • 1851 published by Frederick Scott Archer[1]
  • used until approximately 1890


steps in evolution:

  • 1847 collodion discovered by Maynard: cellulose nitrate solved in ether[2]
  • 1850 Gustave le Gray already used collodion for making negatives but couldn’t publish an usable process[3]

[edit] process

[edit] preparation

  1. thorough cleaning of the glass plate
  2. seaming or coating of the whole plate with a solution of natural rubber or gelatin, from beginning of the 1870ies also albumen as a substratum[4] [5]
  3. solution of cellulose nitrate in alcohol and ether, addition of potassium iodide (more ether during winter times ), firstly exclusive usage of iodine salts, later mixtures of iodine and bromine: increased light sensitivity, more possible tonal values (used salts: ammonium, cadmium or potassium bromide + potassium iodide)[6] [7] [8] [9] [10] [11]
  4. prepared solution poured on glass plate, spread by moving the plate and excess poured off over one corner (this originates the characteristic thumbprint in one corner)[12]


Since the plate has to be processed moistly, there are already early experiments to keep the collodion damp by adding other coatings made of e.g. albumen, glycerol, honey.[13]

Without an additional coating the plate stays moist for approximately one hour, within that the plate has to be exposed, developed and fixed (the pores of the collodion have to be open to let the process chemicals permeate, otherwise through partial drying the image becomes stained)[14]

[edit] sensitization

  • bath in solution of silver nitrate[15]
  • addition of potassium iodide and nitric acid[16]

[edit] exposure

exposure time: few seconds (considerably less than daguerreotype and calotype)[17]

[edit] development

time until development has to take place: 10 to 20 minutes, less in dry weather[18]

different formulations:

  • ferric sulfate acidulated by hydrochloric acid, nitric, citric, sulfuric or acidic acid (restrains development, improves fluidity), addition of silver or silver nitrate not necessary for physical development since silver ions present from the moist collodion coating[19] [20] [21] [22] [23]
  • alkaline or acetatic solution of ammonium ferric sulfate (slow development, soft tonality)[24]
  • from 1851 on shortly in use: pyrogallic acid (fast development, intense tonality)[25] [26] [27] [28]
  • combination of ammonium ferric sulfate and pyrogallic acid[29]
  • 1844: green vitriol (Robert Hunt)[30] [31]
  • addition of mercuric iodide (decreasing the blackening of the silver)[32]

image develops not within the collodion layer, but at the surface[33]

[edit] fixing

  • sodium thiosulfate or potassium cyanide (stronger contrast than with sodium thiosulfate, weaker image, works faster and clears negatives)[34] [35] [36] [37] [38]
  • potassium cyanide in 2% solution[39]
  • sodium thiosulfate in 40% solution

[edit] post treatment

  • coatings[40] [41] [42] [43]
    • protection varnish: collodion plates were mostly varnished since the surface is mechanically very sensitive
      • coatings of natural resins (+ additives): e.g. resins (amber, copal, shellac (comparatively hard), sandarac, mastic, dammar, benzoin, turpentine): especially shellac on collodion plates good protection against scratching), yellow/ red collodion and mixtures
      • matting of the protection varnish by abrasion with pulverized cuttle-bone or dextrin colophony[44]
    • base for retouching/ pre coating (sometimes only partial coating):
      • protein-, gum- or rubber-based coatings or other water soluble substances (e.g. gum arabic, albumen, gelatin, dextrin)
      • also as intermediate coating to protect the collodion against an alcohol-solved varnish
      • addition of sandarac (especially in retouching-base formulas, comparatively cheap)
    • protection during wet processing/ masking for partial intensification or other chemical ost-treatments:

this coating was often removed directly after completion of the plate

    • additives: gutta-percha, asphalt, rubber, oil (e.g. spirits of turpentine or lavender as plasticizer)
    • solvents: mostly alcohol as solvent for resins (evaporates quickly during warm application, no risk of condensation or reticulation)
    • application:
      • brushing or pouring on
      • immersion
      • warm (mostly with resins) or cold (resins, proteins, polysaccharides, often less mechanically stable, softer) application
      • for warm application plate has to be warmed first: many risks (probably cause for later damage)[45]


  • retouching
  • after 1868 negative retouching in portraits was very much in use
  • retouching for minimizing of flaws (holes, hairs, scratches, dust in the emulsion) and for compensation of spectrally inhomogeneous sensitivity of the plates (sky often over-exposed, thus missing clouds, reddish skin irritations under-exposed, thus very dark in the resulting positive print)
      • Indian ink or Indian red (opaque watercolor)
      • masking with Fuchsin or Karmine in natural rubber ,
      • chalk color or affixed paper on the glass side,
      • scumbles (color acts as a filter for some spectral parts of the light) to extenuate or accentuate parts of the image
      • pencil retouching on emulsion side (end of the 19th century): before that minimizing dust or similar with bluish or grey watercolor, matting coating on the glass side lets retouching appear softer

typical post treatment for a collodion glass plate negative: coating of gum arabic, retouching with watercolor, protection varnish of shellac, sandarac or dammar, then pencil retouching[50]

very often intensification with e.g.

    • hydroquinone
    • citric acid
    • silver nitrate
    • mercuric chloride with subsequent ammonia (intensification/ reduction)
    • lead nitrate with subsequent fixing (intensification)
    • silver
    • silver + copper
    • lead
    • mercury (intensification)

[edit] variations

1855: strippable collodion pellicles by F. Scott Archer (with gutta-percha) as possibility to store negative foils or for transferring to a new base material[54] [55]

[edit] pseudo-positives

  • already 1839 it’s been noticed that thin (under-exposed) negatives appear positive against a dark background

Hence amphitypes", "amphi-positives", "melainotypes" are generated ", i.e. weakly exposed and developed negatives or negatives reduced by additional treatment in „alabastrine solution“ (water, ferrous sulfate, mercuric chloride, sodium chloride), thus the image silver becomes whitish.[56]

These negatives get a black or dark brown background and seem to be positive.

These processes are a cheap alternative for a daguerreotype. Especially popular in the US.

  • all pseudo-positives firstly are called melainotypes; later on only photographs on an iron plate get that name (which thereafter are called tintypes).[57]
  • around 1852 invention of ambrotype and tintype (main examples of pseudo-positives)
  • from 1870 on also plates with a brown background: vivid image with pleasing image tone (Tintypes of this kind are then „chocolate tinting")[58] [59]
  • exposure time for ambrotype and tintype is approximately 6 to 10 seconds.[60]


[edit] ambrotype

  • 1851 published by Frederick Scott Archer and Peter W. Fry.[61]
  • popular period 1854-56/7, after that only rarely until 1881, mainly used for portrait making.[62]
  • general process: collodion negative on glass, dark background (paper, metal, velvet, varnish).

Case or mounting similar to that of daguerreotypes.

  • true sided or not (clothing or setting in portraits can give a hint)

Photographic layer can be directed towards the beholder or not, in the first case there is an additional cover glass on top of the negative (this is the case especially with hand-colored plates), in the second case the glass base itself acts as a cover glass (in this case the black varnish can be applied directly on the photographic layer, very often with a transparent intermediate varnish).[63] [64] [65]

Due to the narrow contact between the photographic layer and the black background in the second case the image appears very sharp and rich in contrast.

  • the highlights (image silver) are often yellowed or greyish.[66]

Some variations:[67]

  • Ambrotypes made on red-, violet- or pink-colored glass (the last one can be mixed up with tintypes), here no dark background is necessary.[68] [69] [70]
  • RELIEVO-AMBROTYPE: 1857 by Thos. C. Lawrence: 3D-effect by only partial black varnish in the area where the portrayed person can be seen (the background is left unvarnished), slight shading onto a white background or third glass plate, photographic background can also be totally scraped off and displaced by a hand-colored background (also called FOIL BACK PHOTOGRAPH).[71]
  • LAMPRATYPE by S.A. Holmes: increased contrast by a leather-polished collodion surface
  • DOUBLE (CEMENTED) GLASS PROCESS (1854): a cover glass (or leather) is glued against the collodion surface to increase stability (e.g. with Canada balsam)
  • ALABASTRINE POSITIVES: after treatment in Alabastrine solution plates are coated with a white copal varnish, whereby colors from hand-coloring can diffuse into the collodion layer and give a much more brilliant coloring

[edit] Ferrotype/ Tintype (USA)

  • 1853 published by Adolphe Martin
  • general process: collodion negatives on a double-sided black or brown varnished tinplate (little later also used on different base-materials like leather, rubber or other metals).

(TAFT, ROBERT, 1964, p 153 et seq.)

  • especially used by street photographers, more in the US than in Europe.[72]
  • first photo booths (e.g. Bosco-automat) around 1900 work with ferrotypes.
  • preparation and development like as in ambrotypes
  • mostly low-contrast.[73]

Ferrotypes are mounted in cases similar to daguerreotype or ambrotype, cardboard frames or little albums, images always side-inverted.[74]

Mainly portraits in different formats, also very small (e.g. gem-portraits: mounted in carte-de-visite).[75]

  • black varnish made of asphalt, lampblack, linseed oil, also mastic or copal[76]
  • Often protection varnish on photographic layer[77]
  • until 1900 mainly made by the wet collodion process. After 1880 until 1910 also by gelatin emulsions (dull, grey images), from 1900 to 1940 dry silver bromide collodion emulsions were in use.
  • process was revived until WW2[78]
  • used again in the 1970ies.[79]

variations melanograph: collodion emulsion on black paper[80]

[edit] pannotype

  • 1853 published by the company Wulff + Co.
  • only used until 1859/60 since the material is very unstable (photographic layer easily gets cracked). *displaced by the ferrotype process.[81]
  • general process: collodion negative on blackened waxed cloth to which the photographic emulsion is transferred after it got developed, separation of the collodion in a bath of sulfuric acid (1:20)[82]


[edit] Gallery

[edit] References

  1. ? NATIONAL MUSEUM OF PHOTOGRAPHY, FILM AND TELEVISION, 2000; McCABE, CONSTANCE, 1991
  2. ? NADEAU, LUIS, 2006, p 58
  3. ? EDER, JOSEF MARIA, 1932, p 477; NADEAU, LUIS, 2006, p 58
  4. ? HANSCH, MARTIN, 1985, p 55 et seq.
  5. ? WEINSTEIN, ROBERT A.; BOOTH, LARRY, 1977, p 175
  6. ? TAFT, ROBERT, 1964, p 118 et seq.
  7. ? NORRIS, DEBBIE HESS, 1989d
  8. ? HANSCH, MARTIN, 1985, p 58
  9. ? EDER, JOSEF MARIA, 1932, p 501
  10. ? TAFT, ROBERT, 1964, p 129
  11. ? GILLET et al., 1986
  12. ? TAFT, ROBERT, 1964, p 118 et seq.
  13. ? NORRIS, DEBBIE HESS, 1989c
  14. ? TAFT, ROBERT, 1964, p 118 et seq.; HANSCH, MARTIN, 1985, p 60
  15. ? NORRIS, DEBBIE HESS, 1989d
  16. ? HANSCH, MARTIN, 1985, p 58
  17. ? NADEAU, LUIS, 2006, p 58
  18. ? HANSCH, MARTIN, 1985, p 58; GRAY, HELEN; GENT, MEGAN, 1998
  19. ? NORRIS, DEBBIE HESS, 1989c
  20. ? HANSCH, MARTIN, 1985, p 58
  21. ? TAFT, ROBERT, 1964, p 118 et seq.
  22. ? NORRIS, DEBBIE HESS, 1989d
  23. ? NORRIS, DEBBIE HESS, 1989d
  24. ? GILLET et al., 1986
  25. ? EDER, JOSEF MARIA, 1932, p 454
  26. ? TAFT, ROBERT, 1964, p 118 et seq.
  27. ? NORRIS, DEBBIE HESS, 1989c
  28. ? GILLET et al., 1986
  29. ? GILLET et al., 1986
  30. ? EDER, JOSEF MARIA, 1932, p 445 et seq.
  31. ? HANSCH, MARTIN, 1985, p 58
  32. ? NORRIS, DEBBIE HESS, 1989d
  33. ? GILLET et al., 1986
  34. ? NORRIS, DEBBIE HESS, 1989c
  35. ? HANSCH, MARTIN, 1985, p 60
  36. ? TAFT, ROBERT, 1964, p 118 et seq.
  37. ? NORRIS, DEBBIE HESS, 1989d
  38. ? EDER, JOSEF MARIA, 1932, p 503 et seq.
  39. ? GILLET et al., 1986
  40. ? NORRIS, DEBBIE HESS, 1989d
  41. ? McCABE, CONSTANCE, 1991
  42. ? GILLET et al., 1986
  43. ? PEDERSEN et al., 2005
  44. ? PEDERSEN et al., 2005
  45. ? NORRIS, DEBBIE HESS, 1989c
  46. ? WEINSTEIN, ROBERT A.; BOOTH, LARRY, 1977, p 175
  47. ? NORRIS, DEBBIE HESS, 1989c
  48. ? GILLET et al., 1986
  49. ? PEDERSEN et al., 2005
  50. ? PEDERSEN et al., 2005
  51. ? HANSCH, MARTIN, 1985, p 60
  52. ? NORRIS, DEBBIE HESS, 1989c
  53. ? GILLET et al., 1986
  54. ? EDER, JOSEF MARIA, 1932, p 480
  55. ? ADELSTEIN, P. Z., 1987
  56. ? HANSCH, MARTIN, 1985, p 40 et seqq.
  57. ? EDER, JOSEF MARIA, 1932, p 513 et seq.
  58. ? HANSCH, MARTIN, 1985, p 41
  59. ? WEINSTEIN, ROBERT A.; BOOTH, LARRY, 1977, p 163
  60. ? TAFT, ROBERT, 1964, p 164
  61. ? NADEAU, LUIS, 2006, p 25
  62. ? TAFT, ROBERT, 1964, p 123 et seqq.
  63. ? HANSCH, MARTIN, 1985, p 42
  64. ? WEINSTEIN, ROBERT A.; BOOTH, LARRY, 1977
  65. ? NADEAU, LUIS, 2006, p 25
  66. ? HANSCH, MARTIN, 1985, p 42
  67. ? NADEAU, LUIS, 2006, p 25 et seq.
  68. ? NORRIS, DEBBIE HESS, 1989d
  69. ? HANSCH, MARTIN, 1985, p 41
  70. ? NADEAU, LUIS, 2006, p 25
  71. ? NADEAU, LUIS, 2006, p 196
  72. ? NADEAU, LUIS, 2006, p 84
  73. ? NORRIS, DEBBIE HESS, 1989e
  74. ? TAFT, ROBERT, 1964, p 162
  75. ? WEINSTEIN, ROBERT A.; BOOTH, LARRY, 1977, p 164
  76. ? NORRIS, DEBBIE HESS, 1989e
  77. ? WEINSTEIN, ROBERT A.; BOOTH, LARRY, 1977, p 162
  78. ? HANSCH, MARTIN, 1985, p 41
  79. ? NADEAU, LUIS, 2006, p 84
  80. ? NADEAU, LUIS, 2006, p 129
  81. ? EDER, JOSEF MARIA, 1932, p 513
  82. ? HANSCH, MARTIN, 1985, p 52 et seq
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