Variations on a Theme
The Ambrotype was a variation on the Collodion process, popular in the US, in which the (normally negative)
image was made to look positive by placing it over a very dark background - the silver particles in the
darkened plate would then reflect more light than the background so that a positive image was produced.
Around the same time the Tintype or Ferrotype process became popular - these were broadly the same as
Ambrotypes except that the collodion was spread over a sheet of blackened or enameled iron to provide
the dark background. The results were not as fine as Ambrotype or Collodion images.
Dry Plates
The Collodion process was overtaken in the 1870's by the 'dry plate' technique, which used an emulsion
of silver bromide and gelatine on glass. These plates were much more sensitive than the collodion plates,
although somewhat grainier. This fact was tolerated since most prints were made by contact processes that
would hide any graininess in the negative. In fact the improved sensitivity was a disadvantage for some
photographers because their cameras were not equiped to make the necessary short exposures, and their
studios were bright enough to cause the plates to fog.
Flexible Film
The first flexible photographic film was marketed in 1889 by George Eastman. This was a film of cellulose
nitrate which was sold as a roll and which could be loaded into mass-produced simple box cameras.
The cameras were sold with the film pre-loaded, and when used the whole camera was sent back to the factory where the film
was extracted and processed. The camera was reloaded with film and returned to the customer. Cellulose nitrate
is highly flammable, with similar properties to guncotton, hence its use was superseded by triacetate films,
and in the 1960's by polymer based plastic films.
Experiments in Color
Color photography had first become a reality in 1861, when the physicist James Clerk-Maxwell experimented
with colored filters. He found that by taking three exposures of the same scene through red, green and blue
filters and then projecting each through its respective filter so that all three images overlapped, he could
recreate the full range of color information present in the original scene.
Advanced Color - the Autochrome Process
In 1906 the Lumiere brothers patented a color photography technique in which multicolored grains of potato
starch (dyed red, green and blue) were painted over a photographic plate, followed by a dusting of lamp black
to fill in the spaces between the microscopic grains. When exposed to a colored scene, the grains acted as
colored filters so that minute patches of the underlying film were exposed only to certain colors of light.
When developed and viewed by transmitted light through the same colored starch grain filters, the original
color was restored and a full color photograph could be seen. This was known as the Autochrome technique
and produced remarkably good results, especially if the plates were subjected to pressure before exposure
to flatten the starch grains.
Modern Color - Kodachrome
Kodachrome, the first modern three-layer dye-based color film, was not produced until 1936. This contains
three separate layers, each sensitive to either red, green or blue light, allowing a single exposure to
produce a full color photograph. Developing a color film is a more complex procedure, in which the silver
particles in each layer are replaced with different colored dyes to recreate the original color.
Self-Developing Film - Polaroid
Polaroid had produced the first instant black and white film in 1948, and in 1963 produced their first
instant color film. These films are distributed in a pack containing the necessary developing chemicals
which are released when the film is squeezed by a roller after the photograph has been taken. The chemicals
are present in multiple layers within the film, as well as in a mass that is spread over the film by the
rollers and sets the development process in motion. Complex reactions involving diffusion and neutralisation
of the various substances ensure that the film is developed in the correct sequence and for the correct
amount of time to produce a good image.
Variations on a Theme
The Ambrotype was a variation on the Collodion process, popular in the US, in which the (normally negative)
image was made to look positive by placing it over a very dark background - the silver particles in the
darkened plate would then reflect more light than the background so that a positive image was produced.
Around the same time the Tintype or Ferrotype process became popular - these were broadly the same as
Ambrotypes except that the collodion was spread over a sheet of blackened or enameled iron to provide
the dark background. The results were not as fine as Ambrotype or Collodion images.
Dry Plates
The Collodion process was overtaken in the 1870's by the 'dry plate' technique, which used an emulsion
of silver bromide and gelatine on glass. These plates were much more sensitive than the collodion plates,
although somewhat grainier. This fact was tolerated since most prints were made by contact processes that
would hide any graininess in the negative. In fact the improved sensitivity was a disadvantage for some
photographers because their cameras were not equiped to make the necessary short exposures, and their
studios were bright enough to cause the plates to fog.
Flexible Film
The first flexible photographic film was marketed in 1889 by George Eastman. This was a film of cellulose
nitrate which was sold as a roll and which could be loaded into mass-produced simple box cameras.
The cameras were sold with the film pre-loaded, and when used the whole camera was sent back to the factory where the film
was extracted and processed. The camera was reloaded with film and returned to the customer. Cellulose nitrate
is highly flammable, with similar properties to guncotton, hence its use was superseded by triacetate films,
and in the 1960's by polymer based plastic films.
Experiments in Color
Color photography had first become a reality in 1861, when the physicist James Clerk-Maxwell experimented
with colored filters. He found that by taking three exposures of the same scene through red, green and blue
filters and then projecting each through its respective filter so that all three images overlapped, he could
recreate the full range of color information present in the original scene.
Advanced Color - the Autochrome Process
In 1906 the Lumiere brothers patented a color photography technique in which multicolored grains of potato
starch (dyed red, green and blue) were painted over a photographic plate, followed by a dusting of lamp black
to fill in the spaces between the microscopic grains. When exposed to a colored scene, the grains acted as
colored filters so that minute patches of the underlying film were exposed only to certain colors of light.
When developed and viewed by transmitted light through the same colored starch grain filters, the original
color was restored and a full color photograph could be seen. This was known as the Autochrome technique
and produced remarkably good results, especially if the plates were subjected to pressure before exposure
to flatten the starch grains.
Modern Color - Kodachrome
Kodachrome, the first modern three-layer dye-based color film, was not produced until 1936. This contains
three separate layers, each sensitive to either red, green or blue light, allowing a single exposure to
produce a full color photograph. Developing a color film is a more complex procedure, in which the silver
particles in each layer are replaced with different colored dyes to recreate the original color.
Self-Developing Film - Polaroid
Polaroid had produced the first instant black and white film in 1948, and in 1963 produced their first
instant color film. These films are distributed in a pack containing the necessary developing chemicals
which are released when the film is squeezed by a roller after the photograph has been taken. The chemicals
are present in multiple layers within the film, as well as in a mass that is spread over the film by the
rollers and sets the development process in motion. Complex reactions involving diffusion and neutralisation
of the various substances ensure that the film is developed in the correct sequence and for the correct
amount of time to produce a good image.
Variations on a Theme
The Ambrotype was a variation on the Collodion process, popular in the US, in which the (normally negative)
image was made to look positive by placing it over a very dark background - the silver particles in the
darkened plate would then reflect more light than the background so that a positive image was produced.
Around the same time the Tintype or Ferrotype process became popular - these were broadly the same as
Ambrotypes except that the collodion was spread over a sheet of blackened or enameled iron to provide
the dark background. The results were not as fine as Ambrotype or Collodion images.
Dry Plates
The Collodion process was overtaken in the 1870's by the 'dry plate' technique, which used an emulsion
of silver bromide and gelatine on glass. These plates were much more sensitive than the collodion plates,
although somewhat grainier. This fact was tolerated since most prints were made by contact processes that
would hide any graininess in the negative. In fact the improved sensitivity was a disadvantage for some
photographers because their cameras were not equiped to make the necessary short exposures, and their
studios were bright enough to cause the plates to fog.
Flexible Film
The first flexible photographic film was marketed in 1889 by George Eastman. This was a film of cellulose
nitrate which was sold as a roll and which could be loaded into mass-produced simple box cameras.
The cameras were sold with the film pre-loaded, and when used the whole camera was sent back to the factory where the film
was extracted and processed. The camera was reloaded with film and returned to the customer. Cellulose nitrate
is highly flammable, with similar properties to guncotton, hence its use was superseded by triacetate films,
and in the 1960's by polymer based plastic films.
Experiments in Color
Color photography had first become a reality in 1861, when the physicist James Clerk-Maxwell experimented
with colored filters. He found that by taking three exposures of the same scene through red, green and blue
filters and then projecting each through its respective filter so that all three images overlapped, he could
recreate the full range of color information present in the original scene.
Advanced Color - the Autochrome Process
In 1906 the Lumiere brothers patented a color photography technique in which multicolored grains of potato
starch (dyed red, green and blue) were painted over a photographic plate, followed by a dusting of lamp black
to fill in the spaces between the microscopic grains. When exposed to a colored scene, the grains acted as
colored filters so that minute patches of the underlying film were exposed only to certain colors of light.
When developed and viewed by transmitted light through the same colored starch grain filters, the original
color was restored and a full color photograph could be seen. This was known as the Autochrome technique
and produced remarkably good results, especially if the plates were subjected to pressure before exposure
to flatten the starch grains.
Modern Color - Kodachrome
Kodachrome, the first modern three-layer dye-based color film, was not produced until 1936. This contains
three separate layers, each sensitive to either red, green or blue light, allowing a single exposure to
produce a full color photograph. Developing a color film is a more complex procedure, in which the silver
particles in each layer are replaced with different colored dyes to recreate the original color.
Self-Developing Film - Polaroid
Polaroid had produced the first instant black and white film in 1948, and in 1963 produced their first
instant color film. These films are distributed in a pack containing the necessary developing chemicals
which are released when the film is squeezed by a roller after the photograph has been taken. The chemicals
are present in multiple layers within the film, as well as in a mass that is spread over the film by the
rollers and sets the development process in motion. Complex reactions involving diffusion and neutralisation
of the various substances ensure that the film is developed in the correct sequence and for the correct
amount of time to produce a good image.
Variations on a Theme
The Ambrotype was a variation on the Collodion process, popular in the US, in which the (normally negative)
image was made to look positive by placing it over a very dark background - the silver particles in the
darkened plate would then reflect more light than the background so that a positive image was produced.
Around the same time the Tintype or Ferrotype process became popular - these were broadly the same as
Ambrotypes except that the collodion was spread over a sheet of blackened or enameled iron to provide
the dark background. The results were not as fine as Ambrotype or Collodion images.
Dry Plates
The Collodion process was overtaken in the 1870's by the 'dry plate' technique, which used an emulsion
of silver bromide and gelatine on glass. These plates were much more sensitive than the collodion plates,
although somewhat grainier. This fact was tolerated since most prints were made by contact processes that
would hide any graininess in the negative. In fact the improved sensitivity was a disadvantage for some
photographers because their cameras were not equiped to make the necessary short exposures, and their
studios were bright enough to cause the plates to fog.
Flexible Film
The first flexible photographic film was marketed in 1889 by George Eastman. This was a film of cellulose
nitrate which was sold as a roll and which could be loaded into mass-produced simple box cameras.
The cameras were sold with the film pre-loaded, and when used the whole camera was sent back to the factory where the film
was extracted and processed. The camera was reloaded with film and returned to the customer. Cellulose nitrate
is highly flammable, with similar properties to guncotton, hence its use was superseded by triacetate films,
and in the 1960's by polymer based plastic films.
Experiments in Color
Color photography had first become a reality in 1861, when the physicist James Clerk-Maxwell experimented
with colored filters. He found that by taking three exposures of the same scene through red, green and blue
filters and then projecting each through its respective filter so that all three images overlapped, he could
recreate the full range of color information present in the original scene.
Advanced Color - the Autochrome Process
In 1906 the Lumiere brothers patented a color photography technique in which multicolored grains of potato
starch (dyed red, green and blue) were painted over a photographic plate, followed by a dusting of lamp black
to fill in the spaces between the microscopic grains. When exposed to a colored scene, the grains acted as
colored filters so that minute patches of the underlying film were exposed only to certain colors of light.
When developed and viewed by transmitted light through the same colored starch grain filters, the original
color was restored and a full color photograph could be seen. This was known as the Autochrome technique
and produced remarkably good results, especially if the plates were subjected to pressure before exposure
to flatten the starch grains.
Modern Color - Kodachrome
Kodachrome, the first modern three-layer dye-based color film, was not produced until 1936. This contains
three separate layers, each sensitive to either red, green or blue light, allowing a single exposure to
produce a full color photograph. Developing a color film is a more complex procedure, in which the silver
particles in each layer are replaced with different colored dyes to recreate the original color.
Self-Developing Film - Polaroid
Polaroid had produced the first instant black and white film in 1948, and in 1963 produced their first
instant color film. These films are distributed in a pack containing the necessary developing chemicals
which are released when the film is squeezed by a roller after the photograph has been taken. The chemicals
are present in multiple layers within the film, as well as in a mass that is spread over the film by the
rollers and sets the development process in motion. Complex reactions involving diffusion and neutralisation
of the various substances ensure that the film is developed in the correct sequence and for the correct
amount of time to produce a good image.
Variations on a Theme
The Ambrotype was a variation on the Collodion process, popular in the US, in which the (normally negative)
image was made to look positive by placing it over a very dark background - the silver particles in the
darkened plate would then reflect more light than the background so that a positive image was produced.
Around the same time the Tintype or Ferrotype process became popular - these were broadly the same as
Ambrotypes except that the collodion was spread over a sheet of blackened or enameled iron to provide
the dark background. The results were not as fine as Ambrotype or Collodion images.
Dry Plates
The Collodion process was overtaken in the 1870's by the 'dry plate' technique, which used an emulsion
of silver bromide and gelatine on glass. These plates were much more sensitive than the collodion plates,
although somewhat grainier. This fact was tolerated since most prints were made by contact processes that
would hide any graininess in the negative. In fact the improved sensitivity was a disadvantage for some
photographers because their cameras were not equiped to make the necessary short exposures, and their
studios were bright enough to cause the plates to fog.
Flexible Film
The first flexible photographic film was marketed in 1889 by George Eastman. This was a film of cellulose
nitrate which was sold as a roll and which could be loaded into mass-produced simple box cameras.
The cameras were sold with the film pre-loaded, and when used the whole camera was sent back to the factory where the film
was extracted and processed. The camera was reloaded with film and returned to the customer. Cellulose nitrate
is highly flammable, with similar properties to guncotton, hence its use was superseded by triacetate films,
and in the 1960's by polymer based plastic films.
Experiments in Color
Color photography had first become a reality in 1861, when the physicist James Clerk-Maxwell experimented
with colored filters. He found that by taking three exposures of the same scene through red, green and blue
filters and then projecting each through its respective filter so that all three images overlapped, he could
recreate the full range of color information present in the original scene.
Advanced Color - the Autochrome Process
In 1906 the Lumiere brothers patented a color photography technique in which multicolored grains of potato
starch (dyed red, green and blue) were painted over a photographic plate, followed by a dusting of lamp black
to fill in the spaces between the microscopic grains. When exposed to a colored scene, the grains acted as
colored filters so that minute patches of the underlying film were exposed only to certain colors of light.
When developed and viewed by transmitted light through the same colored starch grain filters, the original
color was restored and a full color photograph could be seen. This was known as the Autochrome technique
and produced remarkably good results, especially if the plates were subjected to pressure before exposure
to flatten the starch grains.
Modern Color - Kodachrome
Kodachrome, the first modern three-layer dye-based color film, was not produced until 1936. This contains
three separate layers, each sensitive to either red, green or blue light, allowing a single exposure to
produce a full color photograph. Developing a color film is a more complex procedure, in which the silver
particles in each layer are replaced with different colored dyes to recreate the original color.
Self-Developing Film - Polaroid
Polaroid had produced the first instant black and white film in 1948, and in 1963 produced their first
instant color film. These films are distributed in a pack containing the necessary developing chemicals
which are released when the film is squeezed by a roller after the photograph has been taken. The chemicals
are present in multiple layers within the film, as well as in a mass that is spread over the film by the
rollers and sets the development process in motion. Complex reactions involving diffusion and neutralisation
of the various substances ensure that the film is developed in the correct sequence and for the correct
amount of time to produce a good image.
Variations on a Theme
The Ambrotype was a variation on the Collodion process, popular in the US, in which the (normally negative)
image was made to look positive by placing it over a very dark background - the silver particles in the
darkened plate would then reflect more light than the background so that a positive image was produced.
Around the same time the Tintype or Ferrotype process became popular - these were broadly the same as
Ambrotypes except that the collodion was spread over a sheet of blackened or enameled iron to provide
the dark background. The results were not as fine as Ambrotype or Collodion images.
Dry Plates
The Collodion process was overtaken in the 1870's by the 'dry plate' technique, which used an emulsion
of silver bromide and gelatine on glass. These plates were much more sensitive than the collodion plates,
although somewhat grainier. This fact was tolerated since most prints were made by contact processes that
would hide any graininess in the negative. In fact the improved sensitivity was a disadvantage for some
photographers because their cameras were not equiped to make the necessary short exposures, and their
studios were bright enough to cause the plates to fog.
Flexible Film
The first flexible photographic film was marketed in 1889 by George Eastman. This was a film of cellulose
nitrate which was sold as a roll and which could be loaded into mass-produced simple box cameras.
The cameras were sold with the film pre-loaded, and when used the whole camera was sent back to the factory where the film
was extracted and processed. The camera was reloaded with film and returned to the customer. Cellulose nitrate
is highly flammable, with similar properties to guncotton, hence its use was superseded by triacetate films,
and in the 1960's by polymer based plastic films.
Experiments in Color
Color photography had first become a reality in 1861, when the physicist James Clerk-Maxwell experimented
with colored filters. He found that by taking three exposures of the same scene through red, green and blue
filters and then projecting each through its respective filter so that all three images overlapped, he could
recreate the full range of color information present in the original scene.
Advanced Color - the Autochrome Process
In 1906 the Lumiere brothers patented a color photography technique in which multicolored grains of potato
starch (dyed red, green and blue) were painted over a photographic plate, followed by a dusting of lamp black
to fill in the spaces between the microscopic grains. When exposed to a colored scene, the grains acted as
colored filters so that minute patches of the underlying film were exposed only to certain colors of light.
When developed and viewed by transmitted light through the same colored starch grain filters, the original
color was restored and a full color photograph could be seen. This was known as the Autochrome technique
and produced remarkably good results, especially if the plates were subjected to pressure before exposure
to flatten the starch grains.
Modern Color - Kodachrome
Kodachrome, the first modern three-layer dye-based color film, was not produced until 1936. This contains
three separate layers, each sensitive to either red, green or blue light, allowing a single exposure to
produce a full color photograph. Developing a color film is a more complex procedure, in which the silver
particles in each layer are replaced with different colored dyes to recreate the original color.
Self-Developing Film - Polaroid
Polaroid had produced the first instant black and white film in 1948, and in 1963 produced their first
instant color film. These films are distributed in a pack containing the necessary developing chemicals
which are released when the film is squeezed by a roller after the photograph has been taken. The chemicals
are present in multiple layers within the film, as well as in a mass that is spread over the film by the
rollers and sets the development process in motion. Complex reactions involving diffusion and neutralisation
of the various substances ensure that the film is developed in the correct sequence and for the correct
amount of time to produce a good image.
Variations on a Theme
The Ambrotype was a variation on the Collodion process, popular in the US, in which the (normally negative)
image was made to look positive by placing it over a very dark background - the silver particles in the
darkened plate would then reflect more light than the background so that a positive image was produced.
Around the same time the Tintype or Ferrotype process became popular - these were broadly the same as
Ambrotypes except that the collodion was spread over a sheet of blackened or enameled iron to provide
the dark background. The results were not as fine as Ambrotype or Collodion images.
Dry Plates
The Collodion process was overtaken in the 1870's by the 'dry plate' technique, which used an emulsion
of silver bromide and gelatine on glass. These plates were much more sensitive than the collodion plates,
although somewhat grainier. This fact was tolerated since most prints were made by contact processes that
would hide any graininess in the negative. In fact the improved sensitivity was a disadvantage for some
photographers because their cameras were not equiped to make the necessary short exposures, and their
studios were bright enough to cause the plates to fog.
Flexible Film
The first flexible photographic film was marketed in 1889 by George Eastman. This was a film of cellulose
nitrate which was sold as a roll and which could be loaded into mass-produced simple box cameras.
The cameras were sold with the film pre-loaded, and when used the whole camera was sent back to the factory where the film
was extracted and processed. The camera was reloaded with film and returned to the customer. Cellulose nitrate
is highly flammable, with similar properties to guncotton, hence its use was superseded by triacetate films,
and in the 1960's by polymer based plastic films.
Experiments in Color
Color photography had first become a reality in 1861, when the physicist James Clerk-Maxwell experimented
with colored filters. He found that by taking three exposures of the same scene through red, green and blue
filters and then projecting each through its respective filter so that all three images overlapped, he could
recreate the full range of color information present in the original scene.
Advanced Color - the Autochrome Process
In 1906 the Lumiere brothers patented a color photography technique in which multicolored grains of potato
starch (dyed red, green and blue) were painted over a photographic plate, followed by a dusting of lamp black
to fill in the spaces between the microscopic grains. When exposed to a colored scene, the grains acted as
colored filters so that minute patches of the underlying film were exposed only to certain colors of light.
When developed and viewed by transmitted light through the same colored starch grain filters, the original
color was restored and a full color photograph could be seen. This was known as the Autochrome technique
and produced remarkably good results, especially if the plates were subjected to pressure before exposure
to flatten the starch grains.
Modern Color - Kodachrome
Kodachrome, the first modern three-layer dye-based color film, was not produced until 1936. This contains
three separate layers, each sensitive to either red, green or blue light, allowing a single exposure to
produce a full color photograph. Developing a color film is a more complex procedure, in which the silver
particles in each layer are replaced with different colored dyes to recreate the original color.
Self-Developing Film - Polaroid
Polaroid had produced the first instant black and white film in 1948, and in 1963 produced their first
instant color film. These films are distributed in a pack containing the necessary developing chemicals
which are released when the film is squeezed by a roller after the photograph has been taken. The chemicals
are present in multiple layers within the film, as well as in a mass that is spread over the film by the
rollers and sets the development process in motion. Complex reactions involving diffusion and neutralisation
of the various substances ensure that the film is developed in the correct sequence and for the correct
amount of time to produce a good image.
Variations on a Theme
The Ambrotype was a variation on the Collodion process, popular in the US, in which the (normally negative)
image was made to look positive by placing it over a very dark background - the silver particles in the
darkened plate would then reflect more light than the background so that a positive image was produced.
Around the same time the Tintype or Ferrotype process became popular - these were broadly the same as
Ambrotypes except that the collodion was spread over a sheet of blackened or enameled iron to provide
the dark background. The results were not as fine as Ambrotype or Collodion images.
Dry Plates
The Collodion process was overtaken in the 1870's by the 'dry plate' technique, which used an emulsion
of silver bromide and gelatine on glass. These plates were much more sensitive than the collodion plates,
although somewhat grainier. This fact was tolerated since most prints were made by contact processes that
would hide any graininess in the negative. In fact the improved sensitivity was a disadvantage for some
photographers because their cameras were not equiped to make the necessary short exposures, and their
studios were bright enough to cause the plates to fog.
Flexible Film
The first flexible photographic film was marketed in 1889 by George Eastman. This was a film of cellulose
nitrate which was sold as a roll and which could be loaded into mass-produced simple box cameras.
The cameras were sold with the film pre-loaded, and when used the whole camera was sent back to the factory where the film
was extracted and processed. The camera was reloaded with film and returned to the customer. Cellulose nitrate
is highly flammable, with similar properties to guncotton, hence its use was superseded by triacetate films,
and in the 1960's by polymer based plastic films.
Experiments in Color
Color photography had first become a reality in 1861, when the physicist James Clerk-Maxwell experimented
with colored filters. He found that by taking three exposures of the same scene through red, green and blue
filters and then projecting each through its respective filter so that all three images overlapped, he could
recreate the full range of color information present in the original scene.
Advanced Color - the Autochrome Process
In 1906 the Lumiere brothers patented a color photography technique in which multicolored grains of potato
starch (dyed red, green and blue) were painted over a photographic plate, followed by a dusting of lamp black
to fill in the spaces between the microscopic grains. When exposed to a colored scene, the grains acted as
colored filters so that minute patches of the underlying film were exposed only to certain colors of light.
When developed and viewed by transmitted light through the same colored starch grain filters, the original
color was restored and a full color photograph could be seen. This was known as the Autochrome technique
and produced remarkably good results, especially if the plates were subjected to pressure before exposure
to flatten the starch grains.
Modern Color - Kodachrome
Kodachrome, the first modern three-layer dye-based color film, was not produced until 1936. This contains
three separate layers, each sensitive to either red, green or blue light, allowing a single exposure to
produce a full color photograph. Developing a color film is a more complex procedure, in which the silver
particles in each layer are replaced with different colored dyes to recreate the original color.
Self-Developing Film - Polaroid
Polaroid had produced the first instant black and white film in 1948, and in 1963 produced their first
instant color film. These films are distributed in a pack containing the necessary developing chemicals
which are released when the film is squeezed by a roller after the photograph has been taken. The chemicals
are present in multiple layers within the film, as well as in a mass that is spread over the film by the
rollers and sets the development process in motion. Complex reactions involving diffusion and neutralisation
of the various substances ensure that the film is developed in the correct sequence and for the correct
amount of time to produce a good image.
Variations on a Theme
The Ambrotype was a variation on the Collodion process, popular in the US, in which the (normally negative)
image was made to look positive by placing it over a very dark background - the silver particles in the
darkened plate would then reflect more light than the background so that a positive image was produced.
Around the same time the Tintype or Ferrotype process became popular - these were broadly the same as
Ambrotypes except that the collodion was spread over a sheet of blackened or enameled iron to provide
the dark background. The results were not as fine as Ambrotype or Collodion images.
Dry Plates
The Collodion process was overtaken in the 1870's by the 'dry plate' technique, which used an emulsion
of silver bromide and gelatine on glass. These plates were much more sensitive than the collodion plates,
although somewhat grainier. This fact was tolerated since most prints were made by contact processes that
would hide any graininess in the negative. In fact the improved sensitivity was a disadvantage for some
photographers because their cameras were not equiped to make the necessary short exposures, and their
studios were bright enough to cause the plates to fog.
Flexible Film
The first flexible photographic film was marketed in 1889 by George Eastman. This was a film of cellulose
nitrate which was sold as a roll and which could be loaded into mass-produced simple box cameras.
The cameras were sold with the film pre-loaded, and when used the whole camera was sent back to the factory where the film
was extracted and processed. The camera was reloaded with film and returned to the customer. Cellulose nitrate
is highly flammable, with similar properties to guncotton, hence its use was superseded by triacetate films,
and in the 1960's by polymer based plastic films.
Experiments in Color
Color photography had first become a reality in 1861, when the physicist James Clerk-Maxwell experimented
with colored filters. He found that by taking three exposures of the same scene through red, green and blue
filters and then projecting each through its respective filter so that all three images overlapped, he could
recreate the full range of color information present in the original scene.
Advanced Color - the Autochrome Process
In 1906 the Lumiere brothers patented a color photography technique in which multicolored grains of potato
starch (dyed red, green and blue) were painted over a photographic plate, followed by a dusting of lamp black
to fill in the spaces between the microscopic grains. When exposed to a colored scene, the grains acted as
colored filters so that minute patches of the underlying film were exposed only to certain colors of light.
When developed and viewed by transmitted light through the same colored starch grain filters, the original
color was restored and a full color photograph could be seen. This was known as the Autochrome technique
and produced remarkably good results, especially if the plates were subjected to pressure before exposure
to flatten the starch grains.
Modern Color - Kodachrome
Kodachrome, the first modern three-layer dye-based color film, was not produced until 1936. This contains
three separate layers, each sensitive to either red, green or blue light, allowing a single exposure to
produce a full color photograph. Developing a color film is a more complex procedure, in which the silver
particles in each layer are replaced with different colored dyes to recreate the original color.
Self-Developing Film - Polaroid
Polaroid had produced the first instant black and white film in 1948, and in 1963 produced their first
instant color film. These films are distributed in a pack containing the necessary developing chemicals
which are released when the film is squeezed by a roller after the photograph has been taken. The chemicals
are present in multiple layers within the film, as well as in a mass that is spread over the film by the
rollers and sets the development process in motion. Complex reactions involving diffusion and neutralisation
of the various substances ensure that the film is developed in the correct sequence and for the correct
amount of time to produce a good image.
Variations on a Theme
The Ambrotype was a variation on the Collodion process, popular in the US, in which the (normally negative)
image was made to look positive by placing it over a very dark background - the silver particles in the
darkened plate would then reflect more light than the background so that a positive image was produced.
Around the same time the Tintype or Ferrotype process became popular - these were broadly the same as
Ambrotypes except that the collodion was spread over a sheet of blackened or enameled iron to provide
the dark background. The results were not as fine as Ambrotype or Collodion images.
Dry Plates
The Collodion process was overtaken in the 1870's by the 'dry plate' technique, which used an emulsion
of silver bromide and gelatine on glass. These plates were much more sensitive than the collodion plates,
although somewhat grainier. This fact was tolerated since most prints were made by contact processes that
would hide any graininess in the negative. In fact the improved sensitivity was a disadvantage for some
photographers because their cameras were not equiped to make the necessary short exposures, and their
studios were bright enough to cause the plates to fog.
Flexible Film
The first flexible photographic film was marketed in 1889 by George Eastman. This was a film of cellulose
nitrate which was sold as a roll and which could be loaded into mass-produced simple box cameras.
The cameras were sold with the film pre-loaded, and when used the whole camera was sent back to the factory where the film
was extracted and processed. The camera was reloaded with film and returned to the customer. Cellulose nitrate
is highly flammable, with similar properties to guncotton, hence its use was superseded by triacetate films,
and in the 1960's by polymer based plastic films.
Experiments in Color
Color photography had first become a reality in 1861, when the physicist James Clerk-Maxwell experimented
with colored filters. He found that by taking three exposures of the same scene through red, green and blue
filters and then projecting each through its respective filter so that all three images overlapped, he could
recreate the full range of color information present in the original scene.
Advanced Color - the Autochrome Process
In 1906 the Lumiere brothers patented a color photography technique in which multicolored grains of potato
starch (dyed red, green and blue) were painted over a photographic plate, followed by a dusting of lamp black
to fill in the spaces between the microscopic grains. When exposed to a colored scene, the grains acted as
colored filters so that minute patches of the underlying film were exposed only to certain colors of light.
When developed and viewed by transmitted light through the same colored starch grain filters, the original
color was restored and a full color photograph could be seen. This was known as the Autochrome technique
and produced remarkably good results, especially if the plates were subjected to pressure before exposure
to flatten the starch grains.
Modern Color - Kodachrome
Kodachrome, the first modern three-layer dye-based color film, was not produced until 1936. This contains
three separate layers, each sensitive to either red, green or blue light, allowing a single exposure to
produce a full color photograph. Developing a color film is a more complex procedure, in which the silver
particles in each layer are replaced with different colored dyes to recreate the original color.
Self-Developing Film - Polaroid
Polaroid had produced the first instant black and white film in 1948, and in 1963 produced their first
instant color film. These films are distributed in a pack containing the necessary developing chemicals
which are released when the film is squeezed by a roller after the photograph has been taken. The chemicals
are present in multiple layers within the film, as well as in a mass that is spread over the film by the
rollers and sets the development process in motion. Complex reactions involving diffusion and neutralisation
of the various substances ensure that the film is developed in the correct sequence and for the correct
amount of time to produce a good image.
Variations on a Theme
The Ambrotype was a variation on the Collodion process, popular in the US, in which the (normally negative)
image was made to look positive by placing it over a very dark background - the silver particles in the
darkened plate would then reflect more light than the background so that a positive image was produced.
Around the same time the Tintype or Ferrotype process became popular - these were broadly the same as
Ambrotypes except that the collodion was spread over a sheet of blackened or enameled iron to provide
the dark background. The results were not as fine as Ambrotype or Collodion images.
Dry Plates
The Collodion process was overtaken in the 1870's by the 'dry plate' technique, which used an emulsion
of silver bromide and gelatine on glass. These plates were much more sensitive than the collodion plates,
although somewhat grainier. This fact was tolerated since most prints were made by contact processes that
would hide any graininess in the negative. In fact the improved sensitivity was a disadvantage for some
photographers because their cameras were not equiped to make the necessary short exposures, and their
studios were bright enough to cause the plates to fog.
Flexible Film
The first flexible photographic film was marketed in 1889 by George Eastman. This was a film of cellulose
nitrate which was sold as a roll and which could be loaded into mass-produced simple box cameras.
The cameras were sold with the film pre-loaded, and when used the whole camera was sent back to the factory where the film
was extracted and processed. The camera was reloaded with film and returned to the customer. Cellulose nitrate
is highly flammable, with similar properties to guncotton, hence its use was superseded by triacetate films,
and in the 1960's by polymer based plastic films.
Experiments in Color
Color photography had first become a reality in 1861, when the physicist James Clerk-Maxwell experimented
with colored filters. He found that by taking three exposures of the same scene through red, green and blue
filters and then projecting each through its respective filter so that all three images overlapped, he could
recreate the full range of color information present in the original scene.
Advanced Color - the Autochrome Process
In 1906 the Lumiere brothers patented a color photography technique in which multicolored grains of potato
starch (dyed red, green and blue) were painted over a photographic plate, followed by a dusting of lamp black
to fill in the spaces between the microscopic grains. When exposed to a colored scene, the grains acted as
colored filters so that minute patches of the underlying film were exposed only to certain colors of light.
When developed and viewed by transmitted light through the same colored starch grain filters, the original
color was restored and a full color photograph could be seen. This was known as the Autochrome technique
and produced remarkably good results, especially if the plates were subjected to pressure before exposure
to flatten the starch grains.
Modern Color - Kodachrome
Kodachrome, the first modern three-layer dye-based color film, was not produced until 1936. This contains
three separate layers, each sensitive to either red, green or blue light, allowing a single exposure to
produce a full color photograph. Developing a color film is a more complex procedure, in which the silver
particles in each layer are replaced with different colored dyes to recreate the original color.
Self-Developing Film - Polaroid
Polaroid had produced the first instant black and white film in 1948, and in 1963 produced their first
instant color film. These films are distributed in a pack containing the necessary developing chemicals
which are released when the film is squeezed by a roller after the photograph has been taken. The chemicals
are present in multiple layers within the film, as well as in a mass that is spread over the film by the
rollers and sets the development process in motion. Complex reactions involving diffusion and neutralisation
of the various substances ensure that the film is developed in the correct sequence and for the correct
amount of time to produce a good image.
Variations on a Theme
The Ambrotype was a variation on the Collodion process, popular in the US, in which the (normally negative)
image was made to look positive by placing it over a very dark background - the silver particles in the
darkened plate would then reflect more light than the background so that a positive image was produced.
Around the same time the Tintype or Ferrotype process became popular - these were broadly the same as
Ambrotypes except that the collodion was spread over a sheet of blackened or enameled iron to provide
the dark background. The results were not as fine as Ambrotype or Collodion images.
Dry Plates
The Collodion process was overtaken in the 1870's by the 'dry plate' technique, which used an emulsion
of silver bromide and gelatine on glass. These plates were much more sensitive than the collodion plates,
although somewhat grainier. This fact was tolerated since most prints were made by contact processes that
would hide any graininess in the negative. In fact the improved sensitivity was a disadvantage for some
photographers because their cameras were not equiped to make the necessary short exposures, and their
studios were bright enough to cause the plates to fog.
Flexible Film
The first flexible photographic film was marketed in 1889 by George Eastman. This was a film of cellulose
nitrate which was sold as a roll and which could be loaded into mass-produced simple box cameras.
The cameras were sold with the film pre-loaded, and when used the whole camera was sent back to the factory where the film
was extracted and processed. The camera was reloaded with film and returned to the customer. Cellulose nitrate
is highly flammable, with similar properties to guncotton, hence its use was superseded by triacetate films,
and in the 1960's by polymer based plastic films.
Experiments in Color
Color photography had first become a reality in 1861, when the physicist James Clerk-Maxwell experimented
with colored filters. He found that by taking three exposures of the same scene through red, green and blue
filters and then projecting each through its respective filter so that all three images overlapped, he could
recreate the full range of color information present in the original scene.
Advanced Color - the Autochrome Process
In 1906 the Lumiere brothers patented a color photography technique in which multicolored grains of potato
starch (dyed red, green and blue) were painted over a photographic plate, followed by a dusting of lamp black
to fill in the spaces between the microscopic grains. When exposed to a colored scene, the grains acted as
colored filters so that minute patches of the underlying film were exposed only to certain colors of light.
When developed and viewed by transmitted light through the same colored starch grain filters, the original
color was restored and a full color photograph could be seen. This was known as the Autochrome technique
and produced remarkably good results, especially if the plates were subjected to pressure before exposure
to flatten the starch grains.
Modern Color - Kodachrome
Kodachrome, the first modern three-layer dye-based color film, was not produced until 1936. This contains
three separate layers, each sensitive to either red, green or blue light, allowing a single exposure to
produce a full color photograph. Developing a color film is a more complex procedure, in which the silver
particles in each layer are replaced with different colored dyes to recreate the original color.
Self-Developing Film - Polaroid
Polaroid had produced the first instant black and white film in 1948, and in 1963 produced their first
instant color film. These films are distributed in a pack containing the necessary developing chemicals
which are released when the film is squeezed by a roller after the photograph has been taken. The chemicals
are present in multiple layers within the film, as well as in a mass that is spread over the film by the
rollers and sets the development process in motion. Complex reactions involving diffusion and neutralisation
of the various substances ensure that the film is developed in the correct sequence and for the correct
amount of time to produce a good image.
Variations on a Theme
The Ambrotype was a variation on the Collodion process, popular in the US, in which the (normally negative)
image was made to look positive by placing it over a very dark background - the silver particles in the
darkened plate would then reflect more light than the background so that a positive image was produced.
Around the same time the Tintype or Ferrotype process became popular - these were broadly the same as
Ambrotypes except that the collodion was spread over a sheet of blackened or enameled iron to provide
the dark background. The results were not as fine as Ambrotype or Collodion images.
Dry Plates
The Collodion process was overtaken in the 1870's by the 'dry plate' technique, which used an emulsion
of silver bromide and gelatine on glass. These plates were much more sensitive than the collodion plates,
although somewhat grainier. This fact was tolerated since most prints were made by contact processes that
would hide any graininess in the negative. In fact the improved sensitivity was a disadvantage for some
photographers because their cameras were not equiped to make the necessary short exposures, and their
studios were bright enough to cause the plates to fog.
Flexible Film
The first flexible photographic film was marketed in 1889 by George Eastman. This was a film of cellulose
nitrate which was sold as a roll and which could be loaded into mass-produced simple box cameras.
The cameras were sold with the film pre-loaded, and when used the whole camera was sent back to the factory where the film
was extracted and processed. The camera was reloaded with film and returned to the customer. Cellulose nitrate
is highly flammable, with similar properties to guncotton, hence its use was superseded by triacetate films,
and in the 1960's by polymer based plastic films.
Experiments in Color
Color photography had first become a reality in 1861, when the physicist James Clerk-Maxwell experimented
with colored filters. He found that by taking three exposures of the same scene through red, green and blue
filters and then projecting each through its respective filter so that all three images overlapped, he could
recreate the full range of color information present in the original scene.
Advanced Color - the Autochrome Process
In 1906 the Lumiere brothers patented a color photography technique in which multicolored grains of potato
starch (dyed red, green and blue) were painted over a photographic plate, followed by a dusting of lamp black
to fill in the spaces between the microscopic grains. When exposed to a colored scene, the grains acted as
colored filters so that minute patches of the underlying film were exposed only to certain colors of light.
When developed and viewed by transmitted light through the same colored starch grain filters, the original
color was restored and a full color photograph could be seen. This was known as the Autochrome technique
and produced remarkably good results, especially if the plates were subjected to pressure before exposure
to flatten the starch grains.
Modern Color - Kodachrome
Kodachrome, the first modern three-layer dye-based color film, was not produced until 1936. This contains
three separate layers, each sensitive to either red, green or blue light, allowing a single exposure to
produce a full color photograph. Developing a color film is a more complex procedure, in which the silver
particles in each layer are replaced with different colored dyes to recreate the original color.
Self-Developing Film - Polaroid
Polaroid had produced the first instant black and white film in 1948, and in 1963 produced their first
instant color film. These films are distributed in a pack containing the necessary developing chemicals
which are released when the film is squeezed by a roller after the photograph has been taken. The chemicals
are present in multiple layers within the film, as well as in a mass that is spread over the film by the
rollers and sets the development process in motion. Complex reactions involving diffusion and neutralisation
of the various substances ensure that the film is developed in the correct sequence and for the correct
amount of time to produce a good image.