Photograph Collection Survey: Types of Photographs
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Photograph Collection Survey: Types of Photographs Direct Positive Photographs: Daguerreotypes o Most common: 1839-ca. 1860 o Direct print. No negative. Each image unique and one of a kind o Always found in a case Surface is very soft and easily damaged. o How a Daguerreotype is made: Thin coat of pure silver on copper given high mirror-like polish Sensitized by exposure to iodine fumes The image developed by exposure to fumes of heated mercury. Mercury condensed on the plate surface where light had hit during camera exposure. Silver iodide layer dissolved by immersion solution of water & sodium thiosulphate. Light tones of the image are formed by the deposits of mercury, which scattered light Dark tones are formed by specular reflection of the mirror surface of the plate. Surface is exceptionally fragile. Soft silver easily scratched and mercury is easily wiped away. o Highly reflective surface o Image appears positive only under certain lighting conditions and angles of view o Deterioration is caused by pollutants and humid storage environments
Transcript of Photograph Collection Survey: Types of Photographs
Photograph Collection Survey:
Types of Photographs
Direct Positive Photographs:
Daguerreotypes
o Most common: 1839-ca. 1860
o Direct print.
No negative.
Each image unique and one of a
kind
o Always found in a case
Surface is very soft and easily
damaged.
o How a Daguerreotype is made:
Thin coat of pure silver on copper
given high mirror-like polish
Sensitized by exposure to iodine
fumes
The image developed by exposure to fumes of heated mercury.
Mercury condensed on the plate surface where light had hit during
camera exposure.
Silver iodide layer dissolved by immersion solution of water & sodium
thiosulphate.
Light tones of the image are formed by the deposits of mercury, which
scattered light
Dark tones are formed by specular reflection of the mirror surface of the
plate.
Surface is exceptionally fragile. Soft silver easily scratched and mercury is
easily wiped away.
o Highly reflective surface
o Image appears positive only under certain lighting conditions and angles of view
o Deterioration is caused by pollutants and humid storage environments
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o Never touch the surface. Only the case or exterior glass.
o Never take apart yourself, contact the photograph curator
o If seal is broken, silver will tarnish
Appears as a colored haze (yellow, magenta, or blue)
Attempts to reseal can cause further
damage
o Original glass covers also deteriorate
“Weeping glass” is tiny whitish spots on
the interior side of the glass
Ambrotypes
o Most Common: 1851-ca. 1880
o Thin negative on glass.
o Direct positive print.
No negative.
Each image is unique and made one at a
time in the camera.
o Appear positive by placing a black background
behind it.
o Usually found in a case
To protect supports, often placed in cases
like daguerreotypes and are often mistaken for them
Ambrotypes appear positive no matter the angle of view.
o Parts of an Ambrotype
Outer protective case
Backing of black paper, cloth, or metal
The on-glass, emulsion to the front and the black varnish on the back
Brass die-cut frame
Gilt border of thin brass to edge wrap the frame, glass, and backing.
o Common for them to be colored or tinted.
Especially rouge cheeks and lips, but also buttons, watch chains,
pendants, and broaches
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o Identification by the fact that their images appear as negative when light is
transmitted through the glass support.
o Damage to ambrotypes is often due to the deterioration of the dark backing
destroying the positive/negative effect.
Tintypes
o Also known as ferrotypes and melainotypes
o Most common: 1854-ca. 1930s
o Negative is supported by dark lacquered thin iron sheet
appears as a positive image.
o Like Ambrotypes, could be colored or tinted
o Under glass & in a case, difficult to tell from ambrotypes.
If a magnet does not hold, it is an ambrotype.
If a magnet holds, it is likely a tintype
Darkly varnish metal backings were sometimes
used for ambrotypes.
o Deterioration often result of mishandling
Easily bent which can cause the varnish to crack.
Once air & moisture penetrates iron support, they begin to rust.
o Store tintypes not in cases in paper or plastic enclosures.
Photographic prints: Salted paper prints
o Most common: 1839-ca. 1860s
o Very rare
o Positive photograph printed from negative
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o Support material is ordinary paper
o Printed out solely by natural light
Negative placed in contact with sensitized paper and exposed to sunlight
o Print has a matte surface and warm image tones
Brick red or purple-brown depending on how it was processed and how
the paper is sized
o 1-layer structure: image appears embedded in paper fibers
Albumen prints
o Most common: 1850-ca. 1900
o Predominant paper print process in the 1800s
Began to be replaced by industrial made
gelatin & collodion printing-out papers in
about 1885
o Often sepia toned with a slightly glossy surface
Unfaded albumen prints have a purple-brown
tone, rather then sepia.
o Making an Albumen print
A thin sheet of paper is first coated with egg
whites and salt
Floated on silver nitrate to make it sensitive to light
The image is created by printing under a negative in sunlight.
The finished picture is fixed, washed, and often gold toned before
mounting.
o Since no baryta layer is present, paper fibers visible through the binding.
o No baryta layer
Prints are always mounted
Paper fibers visible through albumen
o Ironically, signs of deterioration often help identify albumen prints.
A clue is localized or overall image fading.
Collodion printed-out photographic prints
o Glossy most common: late 1880s-1920s
o Matte most common: 1894-1920s
o Chief commercial portrait medium 1895-1910.
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o Made with the same sticky nitrocellulose emulsion as ambrotypes and wet plate
negatives mixed with silver chloride and coated onto paper.
o Surfaces can be matte, glossy, or semi-gloss like an albumen print.
o The white areas generally lacked yellowish cast of albumen prints.
o Usually toned with gold or platinum so that images show little or no fading.
o They do not show silver mirroring.
Gelatin silver printed-out photographic prints
o Most common: 1885-1905
o Image developed from direct reaction to light
o Often faded to yellow
o The light sensitive material of silver prints are either silver chloride or silver
bromide or a mixture of both and coated onto the paper in a layer of gelatin.
o Surfaces can be matte, glossy or somewhere in between.
Usually very glossy
o Tones can mimic the silvery grays of platinotypes or the warm browns of
albumen prints, or have a range of other colors.
Black and white silver gelatin developed out prints
o Most common: 1900-present
o Most black and white photographs of the 20th century have been silver gelatin
prints.
o Visible image through use of chemical developer
o Cooler in color (blue, neutral, or black) unless toned
o Made either by contact printing or enlarged from negative
o By 1905, sales of developing-out papers outsold printing-out papers
o Many reasons commercial photographers preferred
Lower costs (no precious metal toning)
Faster & more reliable production
o Amateurs attracted because did not need daylight to expose
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o Most black and white photographs of the 20th century are silver gelatin prints
Platinotypes
o Most common: 1880s-1930s
o Manufactured until World War I
o Revived since 1960 by photographers who like to coat their own paper.
o Widely used for commercial portraiture after the turn of the 20th century.
o With wide range of gray tones, platinotypes are among the most beautiful and
permanent photographs
o In platinotypes, or platinum prints, paper is sensitized with platinum salts.
o Image appears embedded in the paper fibers instead of an emulsion.
o Made with highly stable metallic platinum making them resistant to fading.
o Toning is generally silver to black, but warm browns were also achieved.
o “Ghost” prints
If poor quality paper is left in contact with platinum print, platinum will
accelerate cellulose degradation
Brownish discoloration on paper
Not a transfer print
Cyanotypes
o Most common: 1880-ca. 1910
o Few commercial portraits
Most examples are works by
amateurs.
Often used as proofs.
o Cyanotypes are blue-toned
photographs employing light
sensitive iron salts as opposed to
silver salt
o Mostly commonly on paper
o Exposure to light chemical changes cyanotypes to a colorless or pale brown
form.
o Image can to some extent be reversed when the cyanotype is placed in the dark.
o Alkalis can causes cyanotypes to turn a pale brown color, therefore they should
never be stored in buffered enclosures.
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Place in plastic or unbuffered paper enclosure
Color prints
o Image consists of at least 3 separate gelatin layers, laid one on top of the other
Top to bottom: cyan, magenta, yellow
o Chromogenic process
o Modern color prints have resin coated backing
What makes it difficult to write on backs of photos
o Will fade, even in dark storage
Can use optical or digital tools to color correct
o Only cold storage slows the deterioration of original
o Dye layers may deteriorate at different rates
Image appears to be turning orange is really the cyan layer fading faster
than the magenta and yellow layers
Instant black and white process
o Introduced by Polaroid in 1948 first as sepia and in 1950 as black and white
Instant color process
o Introduced by Polaroid; Polacolor was the first process; SX 70 was introduced in
1972 and Polacolor 2 in 1975
Electrostatic, ink jet, and dye sublimation prints
o Most common: 1985-present
Negatives: Calotype
o Most common: 1841-ca. 1865
o Very rare. None in History Nebraska’s collection
o Paper negative
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Usually waxed or oiled
o Paper fibers visible
o Warm image tone
Collodion wet plate glass negatives
o Most common: 1851-1885
o Collodion: Cellulose nitrate dissolved in ether and alcohol
o Vast improvement and rapidly became forefront of photography
o Many forms: positives, negatives, and transparencies
On opaque supports of glass, ceramic, cloth, leather, metal, paper
o How wet plates are made
Coated a glass plate with thin layer of liquid collodion carrying a dissolved
iodide or bromide salt
Immersed in a bath of silver nitrate solution
Forming silver iodide or silver bromide in pores of the Collodion
Exposed while still wet
Latent image developed with pyrogallic acid
Potassium cyanide or sodium thiosulphate (hypo) used to fix image
Image silver often creamy grayish-yellow hue
Collodion flowed on by hand
Tidal marks & varying thickness
Edges & corners uncoated
Glass plate usually thicker & roughly cut
Common practice to varnish negative
protect against air pollution
Collodion easily dissolved by alcohol
Water normally has no effect
Gelatin dry plate glass negatives
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o Most common: 1880-1920
o Unlike Collodion , Gelatin negatives were
“dry”
o Retained their sensitivity for months
before use
o Could be developed long after exposure
o Could be manufactured industrially,
stored, distributed throughout the world,
and purchased for future use
o Photography no longer exclusive to professionals with darkrooms
o Very common in collections
o Deterioration problems
Physical damage: breaks and cracks
Delamination: emulsion lifting from glass
Poor preparation of glass
Glass deterioration
Exposure to extremely high humidity
All gelatin photographs (negatives & prints) subject to oxidation
Manifests as fading, yellowing, and silver mirroring
Cellulose Nitrate negatives
o Most common: 1889-1951
o Usually have “NITRATE” marked on edge
o Very flammable
Can burn under water
Once ignited, nitrate fires are almost
impossible to put out
Toxic gases produced by burning nitrates are
lethal
o Inherently unstable
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o Unless kept at very low temperature, cellulose nitrate self-destructs at
unpredictable rates
o As it deteriorates, gives off acidic by-products (nitric oxide, nitrogen dioxide)
These gases are deep lung irritants
Repeated exposure may cause eye irritation, rashes, & sores on face &
neck, vertigo, nausea, headaches, swollen glands, & respiratory irritations
Also cause damage to materials around it
Embrittlement of paper & film and cumulative damage to many
organic materials & metals
o Store separately from other photographic material
Well-ventilated
o Maintain a stable environment
Deterioration highly dependent on temperature & relative humidity
32-40˚F with relative humidity of 20-30%
o Best method is to store in a freezer
Slows decomposition (does not stop)
Special archival cold storage materials required
o Use 3 layers of protection
Individual sleeves
Archival, acid-free box
Place box in freezer or on shelf
o Never seal nitrate film in airtight containers
Gases and heat created must be allowed to escape
Acetate negatives
o Most common: 1934-ca. 1960s
o Cellulose acetate, diacetate, triacetate,
etc.
o “SAFETY” marked on edge
Burns with difficulty
o Stability problems
Autocatalytic: once deterioration
has begun, the degradation
produces further damage
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Plastic supports become acidic, shrink and give off a strong vinegar
(acetic acid) smell
o Vinegar Syndrome
When stored in poor environment (high temperature & relative humidity)
or exposed to acidic vapors
Undergoes chemical reaction to form acetic acid
Causes support to become acidic, brittle, and shrink
Six progressive stages
No deterioration.
The negatives begin to curl and they can turn red or blue.
The onset of acetic acid (vinegar smell); also shrinkage and
brittleness.
The warping can begin.
The formation of bubbles and crystals in the film.
The formation of channeling in the film.
Chromogenic color film and transparencies
o Most common: 1935-present
o 3 gelatin image layers, laid one on top of the other
Top to bottom, yellow, magenta, & cyan
Modern films have more complex layered structure
o Chromogenic process
Dye molecules are synthesized during processing
Chromo = Color
-genic = producing
Polyester film
o Most common: 1960-present
o When viewed between polarizing filters, the film is identified by interference
patterns (rainbow colors)
o Much more stable over time than nitrate or acetate film
Card Mounted Photographs Sizes Cigarette card: (1885-1895 & 1909-1917) 2 ¾ x 2 ¾
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Carte de visite: (1859-1900s) 4 1/4 x 2 ½
Victoria: 5” x 3 ¼
Kodak Card: (1880s; circular image) 4 ¼ x 5 ¼
Boudoir: (1890s - ) 5 ½ x 8 ½
Swiss Card: 6 ½ x 2.85
Cabinet Card: (1866-1900) 6 ½ x 4 ½
Imperial: (1890s - ) 7 x 10
Promenade Card: 7 ½ x 4
Paris Card: 9 ¾ x 6 ¾
Panel Card: 13x 7 ½
Stereograph card: (1850s-1920s) 3 ½ x 7 to 5 x 7
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