SHOOTING TECHNIQUES

DAGUERREOTYPE
This invention revolutionizes Europe and United States for suppressing painting and its portraits.
This process, containing a copper plate covered with a layer of silver, made it possible to obtain an image full with details appearing into negative or positive according to the angle under which one looks at it.

CALOTYPE
This process consisted in treating with potassium iodide a paper sheet coated with a solution with silver nitrates.
One obtained negative, then positive by contact with a salted paper. The negative one coated of wax became transparent.

COLLODION
Replacing the Daguerreotype and the calotype, collodion made it possible to obtain negative quickly and very precisely.
These plates, prepared in the black, required a preparation and a very delicate use, obliging the photographers to move with their laboratories.
Nadar, Gray or Watkins was large users of this process.

AMBROTYPE
A glass plate, covered with collodion, was placed on a black bottom. One thus obtained a single positive image, less rich than the daguerreotype.

FERROTYPE
On the basis of iron plate blackened, the ferrotyype was more economic than the daguerreotype. It was mainly used for the portraits by the travelling photographers.

PLAQUE ARGENTIQUE
Containing an emulsion with silver gelatino-bromide (silver gelatin and salts), this process made disappear all the others. At the same time simple and fast, it was preserved a long time before use.

FILM ARGENTIQUE
The silver emulsion is deposited on a flexible film. This one requires revealing and a fixer chemical to provide negative.

PLAQUE AUTOCHROME
In spite of its fragile support, this process was the success of the first slide color.
This plate out of glass was coated with three types of potato flours (red, purple and green) covered with a varnish. The collection Albert Khan comprises several thousands of them.

POLAROID
The polaroid truly developed in ammées the 60, with the appartition of a simple and cheap reliable apparatus. One obtains a positive image in one minute but the tests are degraded quickly in time.

NUMERIQUE
As the silver emulsions rang the knells of the other processes, the numerical one appeared at the end of the Eighties, seems to have to supplant silver chemistry.
Obtained starting from an electronic sensor transforming the image into a binary file displayable by a software on a screen or printable on a support.