Collodion process | Glass collodion negative copy c. 1860 of a daguerreotype of John Quincy Adams in 1847 or 1848, attributed to Mathew Brady ( retouched )

In March 1851, Frederick Scott Archer published his findings in " The Chemist " on the wet plate collodion process.

There are three subsets to the collodion process ; the Ambrotype ( positive image on glass ), the Ferrotype or Tintype ( positive image on metal ) and the negative which was printed on albumen or salt paper.

Several processes were introduced and used for a short time between Niépce's first image and the introduction of the collodion process in 1848.

* James Ambrose Cutting takes out three United States patents for improvements to the wet plate collodion process ( Ambrotype photography ).

The collodion wet plate process that gradually replaced the Daguerreotype during the 1850s required photographers to coat and sensitize thin glass or iron plates shortly before use and expose them in the camera while still wet.

* 1851 – Introduction of the collodion process by Frederick Scott Archer.

He learned the wet-plate collodion process in England, and may have been influenced by some of the great English photographers of those years, such as Julia Margaret Cameron.

The use of paper as a negative meant that the texture and fibers of the paper were visible in prints made from it, leading to an image that was slightly grainy or fuzzy compared to daguerreotypes, which were usually sharp and clear Nevertheless, calotypes — and the salted paper prints that were made from them — remained popular in the United Kingdom and on the European continent outside of France until the collodion process enabled photographers to make glass negatives later in the nineteenth century.

In a business climate where many patent holders were attacked for enforcing their rights, Talbot's behaviour was widely criticized, especially after 1851 when Frederick Scott Archer publicized the collodion process.

The problem was resolved in 1851 ( the year of Daguerre's death ) when the wet collodion process enabled glass to be used as a support ; the lack of detail often found in calotype negatives was removed, and sharp images, similar in detail to the daguerreotype, were created.

The wet collodion negative not only brought about the end of the calotype in commercial use, but also spelled the end of the daguerreotype as a common process for portraiture.

Laroche's side argued that the patent was invalid, as a similar process was invented earlier by Joseph Reade, and that using the collodion process does not infringe the calotype patent anyway, because of significant differences between the two processes.

In the verdict, the jury upheld the calotype patent but agreed that Laroche was not infringing upon it by using the collodion process.

Photographic processes that were invented soon after: ambrotypes and tintypes were mounted in similar cases, but were made by the later wet plate process using collodion on glass or on a bitumen coated iron plate.

The daguerreotype process was far too slow to record anything but the brightest objects, and the wet plate collodion process limited exposures to the time the plate could stay wet.

In 1863 the English chemist William Allen Miller and English amateur astronomer Sir William Huggins used the wet collodion plate process to obtain the first ever photographic spectrogram of a star, Sirius and Capella.

The collodion process is an early photographic process, invented by Frederic Scott Archer.

During the 1880s the collodion process, in turn, was largely replaced by gelatin dry plates — glass plates with a photographic emulsion of silver halides suspended in gelatin.

" Collodion process " is usually taken to be synonymous with the " collodion wet plate process ", a very inconvenient form which required the photographic material to be coated, sensitized, exposed and developed within the span of about fifteen minutes, necessitating a portable darkroom for use in the field.

The wet plate collodion process was still in use in the printing industry in the 1960s for line and tone work ( mostly printed material involving black type against a white background ) as for large work it was much cheaper than gelatin film.

The process is simple: a bromide, iodide, or chloride is dissolved in collodion ( a solution of pyroxylin in alcohol and ether ).

Below is an example of the preparation of a collodion emulsion, from the late 19th century.

This is added to half the collodion made above.

This is then poured into the other half of the collodion ; the brominized collodion dropped in, slowly, while stirring.

To wash, the emulsion is poured into a dish and the solvents are evaporated, until the collodion becomes gelatinous.

Non-flexible collodion is often used in theatrical make-up.

Richard Norris, a doctor of medicine and professor of physiology at Queen's College, Birmingham, is generally credited with the first development of dry collodion plate in the 1860s.

* Non-flexible collodion is used in theatrical makeup for various effects, such as simulating old-age wrinkles or scars.

The collodion is applied to the surface of the optic, usually in two or more layers.

Sometimes a piece of thin cloth is applied between the layers, to hold the collodion together for easy removal.

After the collodion dries and forms a solid sheet covering the optic, it is carefully peeled away taking contamination with it.

Later mantles were made from guncotton ( nitrocellulose ) or collodion rather than ordinary cotton, since extremely fine threads of this material could be produced, but it had to be converted back to cellulose by immersion in ammonium sulfide before first use, since guncotton is highly inflammable and can be explosive.

The negative is traditionally a glass negative with collodion emulsion, but this step can be performed with a modern silver halide negative, too.

This is in contrast to the collodion wet-plate process dominant from the 1850s – 1880s, which had to be exposed and developed immediately after coating.

This is known as self-healing collodion baby.

Dissolved in ether or acetone, it is collodion, used as a wound dressing since the U. S. Civil War.

Silver iodide is always combined with silver bromide or silver chloride, except in the case of some historical processes such as the collodion wet plate and daguerreotype, in which the iodide is sometimes used alone ( generally regarded as necessary if a daguerreotype is to be developed by the Becquerel method, in which exposure to strong red light, which affects only the crystals bearing latent image specks, is substituted for exposure to mercury fumes ).

Victorian sitters who in collodion photographs look as if they are in mourning might have been wearing bright yellow or pink.

In medicine, the term collodion baby applies to newborns who appear to have an extra layer of skin ( known as a collodion membrane ) that has a collodion-like quality.

They wrote " We have heard of a new method of preserving collodion plates for a week or a fortnight discovered by Mr Llewelyn of Penllergare a gentleman to whom all photographers owe a world of thanks.