In
photography
Photography is the visual arts, art, application, and practice of creating images by recording light, either electronically by means of an image sensor, or chemically by means of a light-sensitive material such as photographic film. It is empl ...
, toning is a method of altering the color of
black-and-white photographs. In
analog photography, it is a chemical process carried out on metal salt-based
prints, such as silver prints, iron-based prints (
cyanotype or
Van Dyke brown), or
platinum
Platinum is a chemical element; it has Symbol (chemistry), symbol Pt and atomic number 78. It is a density, dense, malleable, ductility, ductile, highly unreactive, precious metal, precious, silverish-white transition metal. Its name origina ...
or
palladium prints. This
darkroom process cannot be performed with a color photograph. The effects of this process can be emulated with software in
digital photography
Digital photography uses cameras containing arrays of electronic photodetectors interfaced to an analog-to-digital converter (ADC) to produce images focused by a lens, as opposed to an exposure on photographic film. The digitized image is ...
. Sepia is considered a form of black-and-white or
monochrome photography
Monochrome photography is photography where each position on an image can record and show a different ''amount'' of light (Value (color), value), but not a different color (hue). The majority of monochrome photographs produced today are black- ...
.
Chemical toning
Most toners work by replacing the metallic
silver
Silver is a chemical element; it has Symbol (chemistry), symbol Ag () and atomic number 47. A soft, whitish-gray, lustrous transition metal, it exhibits the highest electrical conductivity, thermal conductivity, and reflectivity of any metal. ...
in the
emulsion with a silver compound, such as
silver sulfide (Ag
2S) in the case of sepia toning. The compound may be more stable than metallic silver and may also have a different color or tone. Different toning processes give different colors to the final print. In some cases, the printer may choose to tone some parts of a print more than others.
Toner also can increase the range of shades visible in a print without reducing the contrast.
Selenium
Selenium is a chemical element; it has symbol (chemistry), symbol Se and atomic number 34. It has various physical appearances, including a brick-red powder, a vitreous black solid, and a grey metallic-looking form. It seldom occurs in this elem ...
toning is especially effective in this regard. Some toning processes can improve the chemical stability of the print, increasing its potential longevity. Other toning processes, such as those including iron and copper, can make the print less stable. Many chemical toners are highly toxic, some even containing chemicals that are
carcinogen
A carcinogen () is any agent that promotes the development of cancer. Carcinogens can include synthetic chemicals, naturally occurring substances, physical agents such as ionizing and non-ionizing radiation, and biologic agents such as viruse ...
ic. It is therefore extremely important that the chemicals be used in a well ventilated area, and
rubber gloves and face protection should be worn when handling them.
Selenium toning
Selenium toning is a popular archival toning process, converting metallic silver to
silver selenide. In a diluted toning solution, selenium toning gives a red-brown tone, while a strong solution gives a purple-brown tone. The change in color depends upon the chemical make-up of the photographic emulsion being toned.
Chloro-bromide papers change dramatically, whilst pure
bromide papers change little. Fibre-based papers are more responsive to selenium toning.
Selenium toning may not produce prints quite as stable as
sepia or
gold
Gold is a chemical element; it has chemical symbol Au (from Latin ) and atomic number 79. In its pure form, it is a brightness, bright, slightly orange-yellow, dense, soft, malleable, and ductile metal. Chemically, gold is a transition metal ...
toning. Recently, doubts have surfaced as to the effectiveness of selenium toner in ensuring print longevity.
Sepia toning
Sepia toning is a specialized treatment to give a
black-and-white photographic print a warmer tone and to enhance its archival qualities. The
metal
A metal () is a material that, when polished or fractured, shows a lustrous appearance, and conducts electrical resistivity and conductivity, electricity and thermal conductivity, heat relatively well. These properties are all associated wit ...
lic silver in the print is converted to a
sulfide
Sulfide (also sulphide in British English) is an inorganic anion of sulfur with the chemical formula S2− or a compound containing one or more S2− ions. Solutions of sulfide salts are corrosive. ''Sulfide'' also refers to large families o ...
compound, which is much more resistant to the effects of environmental pollutants such as atmospheric sulfur compounds.
Silver sulfide is at least 50% more stable than silver.
There are three types of sepia toner in modern use:
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Sodium sulfide toners – the traditional "rotten egg" toners (sodium sulfide smells of rotten eggs when exposed to moisture);
#
Thiourea (or "thiocarbamide") toners – these are odorless, and the tone can be varied according to the chemical mixture;
#
Polysulfide or "direct" toners – these do not require a bleaching stage.
Except for polysulfide toners, sepia toning is done in three stages. The print is first soaked in a
potassium ferricyanide bleach to reconvert the metallic silver to
silver halide. The print is washed to remove excess potassium ferricyanide and then immersed into a bath of toner, which converts the silver halides to silver sulfide.
Incomplete bleaching creates a multi-toned image with sepia highlights and gray mid-tones and shadows. This is called ''split toning''. The untoned silver in the print can be treated with a different toner, such as
gold
Gold is a chemical element; it has chemical symbol Au (from Latin ) and atomic number 79. In its pure form, it is a brightness, bright, slightly orange-yellow, dense, soft, malleable, and ductile metal. Chemically, gold is a transition metal ...
or
selenium
Selenium is a chemical element; it has symbol (chemistry), symbol Se and atomic number 34. It has various physical appearances, including a brick-red powder, a vitreous black solid, and a grey metallic-looking form. It seldom occurs in this elem ...
.
Fred Judge
FRPS made extensive use of sepia toning for postcards produced by the British picture postcards manufacturer
Judges Postcards.
Metal replacement toning
Metal replacement toners replace the metallic silver, through a series of chemical reactions, with a
ferrocyanide salt of a
transition metal. Some metals, such as
platinum
Platinum is a chemical element; it has Symbol (chemistry), symbol Pt and atomic number 78. It is a density, dense, malleable, ductility, ductile, highly unreactive, precious metal, precious, silverish-white transition metal. Its name origina ...
or
gold
Gold is a chemical element; it has chemical symbol Au (from Latin ) and atomic number 79. In its pure form, it is a brightness, bright, slightly orange-yellow, dense, soft, malleable, and ductile metal. Chemically, gold is a transition metal ...
, can protect the image. Others, such as
iron
Iron is a chemical element; it has symbol Fe () and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, forming much of Earth's o ...
(''blue'' toner) or
copper
Copper is a chemical element; it has symbol Cu (from Latin ) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish-orang ...
(''red'' toner), may reduce the life of the image.
Metal-replacement toning with gold alone results in a blue-black tone. It is often combined with a sepia toner to produce a more attractive orange-red tone. The archival Gold Protective Solution (GP-1) formula uses a 1% gold chloride stock solution with sodium or potassium thiocyanate. It is sometimes used to split tone photographs previously toned in selenium for artistic purposes.
[Bailey, Jonathan: "Split-Toning:
Processes and Procedures," ''Camera Arts'', February/March 2001.]
Dye toning
Dye toners replace the metallic silver with a
dye. The image will have a reduced lifetime compared with an ordinary silver print.
Digital toning
Toning can be simulated digitally, either in-camera or in
post-processing. The in-camera effect, as well as beginner tutorials given for software like
Photoshop or
GIMP, use a simple tint. More sophisticated
software
Software consists of computer programs that instruct the Execution (computing), execution of a computer. Software also includes design documents and specifications.
The history of software is closely tied to the development of digital comput ...
tends to implement sepia tones using the
duotone feature. Simpler photo-editing software usually has an option to sepia-tone an image in one step.
Examples
The examples below show a digital color photograph, a black-and-white version and a sepia-toned version.
Image:MalibuColor.jpg, Color image
Image:MalibuBW.jpg, Grayscale image
Image:MalibuSepia.jpg, Sepia-toned image
The following are examples of the three types using film:
Image:Freak Out, Oblivion, night.jpg, Color photograph
Image:Titanic-lifeboat.gif, Black-and-white photograph
File:Photograph.sept1895.jpg, Sepia toning
See also
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Color grading
Color grading is a post-production process common to filmmaking and video editing of altering the appearance of an image for presentation in different environments on different devices. Various attributes of an image such as contrast (vision), ...
*
Cyanotype
*
Film tinting
*
Grisaille (painting)
*
*
*
Monochrome
*
Platinum print
Platinum prints, also called ''platinotypes'', are photographic prints made by a monochrome photographic printing, printing process involving platinum.
Platinum tones range from warm black, to reddish brown, to expanded mid-tone grays that are ...
References
External links
Chemical toning (formulas and technique):
(Book) Photographic facts and formulas (1924)Many various toners (copper, iron, vanadium, selenium, sulphide, etc.)(p. 216)
(Book) All about formulae for your darkroom (1942)Selenium, indirect sulphide toning, red chalk, blue and green tones (pp. 44–47)
(Book) Kodak Chemicals and Formulae (1949)Selenium, sulphide-selenium and other toners (pp. 39–41)
Ilford: Toning printsSepia toningin a developing tray.
Digital "toning":
Application to convert digital images
Sepia Effectintage sepia effect in Easy Photo Effects
Sepia toningin the
GIMP
Sepia toning in Java
{{DEFAULTSORT:Photographic Print Toning
Photographic techniques
Monochrome photography