Early Photographic Processes

Gelatino-Bromide Emulsions

1875 - ...

Discovery

Earlier Processes

From the 1850s until the mid-1870s photographers used glass plates coated with collodion, the collodion being wet or dry.

Then experiments began, making the emulsion coating with gelatin, so creating gelatino-bromide emulsion plates.

Gelatine had the advantage of being fluid when warm and a jelly when cold.

Pioneers in the 1870s

Pioneers of the gelatino-bromide process were Mr King, Mr Burgess and Mr Kennett who devised and patented a method of drying the gelatin to form a pellicle, that then needed only to be dissolved in water to be ready for use.

WJ Gough experimented with the process and claimed to obtain greater density in his negatives by including a chloride as well as a bromide in his emulsion, but encountered some difficulties with fogging.

[Article: Gelatino Bromide Emulsion by JW Gough in BJP: 8 Jan 1875; p.15]

Accepted by the 1880s

By the 188s, the Gelatine process had become well established.  The ABC of Modern Photography, published in 1884 said:

[ABC: Page 4]

Process

Advantages of the Gelatino-bromide Process

Rev. AH Palmer spoke highly of the gelatino-bromide process in his communication to Edinburgh Photographic Society, written following his lecture to the society in January 1876.

He described the process as reliable, simple, inexpensive and had the advantage of producing no fumes of ether.  In this communication, he explained the processes he used.

Others described their processes in the British Journal of Photography in the mid-1870s.  Below is an account in 1875 from a contributor describing himself as 'Amateur'.

To make 1 ounce of emulsion ...

1.  Soak 15 grains of Nelson's patent opaque gelatin in a 2 ounce bottle of water for several hours.

2.  Pour off the water and add 2 drachms of distilled water and 18 grains of bromide of potassium.

3.  Place the bottle in hot water until the contents are dissolved

While doing this ...

4.  Dissolve 25 grains of nitrate of silver in 2 drachms of distilled water.

Then take all into the darkroom, and ...

5.  Add the silver to the bromised gelatine gradually, shaking well between each addition.

6.  Add 1 or 2 drachms of methylated spirit.

7.  Add sufficient water to make up the quantity to 1 ounce.

Allow it to rest until the next day

8.  Dialyse for 4 or 5 hours (following Mr King's directions)

To coat the plate ...

The plates should be coated as soon as possible (though in cold weather, the emulsion may keep good for 2 weeks).

1.  Clean the plates well, particularly at the edges.

2.  Guide the emulsion over the plates with a glass rod.

3.  Place the plates on a level dry shelf to dry, covered by a board about 1 inch above, to protect them from falling dust.

The plates should have dried by the next day, and "present a beautiful glossy and transparent appearance like opal glass.

Develop, Fix, Intensify

After exposing the plates they should be laid in a tray of water for a minute or two to soften the film.

1.  Develop in a strong alkaline developer alone.

2.  Fix the plate.

Washing details before and after fixing are not given, except as below.  If the plate needs to be intensified

3.  Immerse the plate in a solution of bichromate of mercury until the picture appears distinctly as a positive by reflected light.

4. Wash

5.  Apply ordinary alkaline developer without the bromide.

Any shade from rich brown to jet black may be obtained.

Modified methods

'Amateur' claimed to have tried almost every modification that he could think of, including the addition of an iodide and a chloride and an excess of silver with aqua regia, added both before and after dialysing the emulsion.

However he found the plain bromised method, described above, to be simpler, more certain and as sensitive as any.

Kennett's Pellicle method

'Amateur' claimed that Kennett's Pellicle emulsion method  was more sensitive, but he had never been able to obtain proper density it, and found that it produced results that  looked cold and more opaque.

He added that if the emulsion described above could be obtained in pellicle form, "collodion might retire from the field".

Using Kennett's Pellicle method avoids the need to follow steps 1 to 7 above.  Instead the grains of the pellicle are dissolved in water, as was described by HP Palmer in his 1876 communication to Edinburgh Photographic Society.

[BJP: 24 Sep 1875; p.462] 

HJ Palmer's Methods

Further comments on the gelatino-bromide process, including  advice on the safelight to be used can be found in Palmer's communication to EPS.

[BJP: 20 Mar 1876; p.113] 

Result

Short exposures are Possible

One of the advantages claimed for the gelatino-bromide process was that it allowed significantly shorter exposure than war required for collodion dry plates.

Rev. AH Palmer reported that on a bright January day he had exposed six plates for times ranging from 10 seconds to two minutes, using a Dallmeyer medium-angle rectilinear lens at the smallest of its five stops.  The plate exposed for 30 seconds he described as 'perfection'.

In Edinburgh 

Presentation of Gelatine Negatives

The Edinburgh professional photographer, James Ross reported, that in his studio, Palmer had exposed and developed a number of gelatine plates and that some of them were very fine.  James Ross said that these plates were quite as rapid as wet collodion, and if they could be made certain, he would have no hesitation in abandoning wet collodion altogether.

On the same evening, James Ross presented the society, in the name of Mr Kennett, with several gelatine negatives, including a portrait of himself.  These were admired.

Discussions

After reading his Paper The Progressive Results of the Past Session, Dr Nicol called the attention of the meeting to a print of the interior of Beverley Cathedral, obtained from Hon A Erskine, which he described as having been taken on a gelatine dry plate with an exposure of a minute and a-quarter  -  less than a hundredth part of what he was sure would have been required by the plates he was in the habit of working.

  AH Palmer's communication on the subject was read to the Society.  The reaction of the Edinburgh photographers to this communication was mixed:

-  Rev Mr Palmer (who two months later was to present a paper on the subject to Edinburgh Photogrpahic Society) described himself as a missionary of gelatine.  After initially encountering considerable difficulties, he now hardly knew what failure was.

-  Mr Pringle said that he had seen Mr Palmer make some experiments with the gelatine plates in their establishment that day, and when exposed side by side with wet collodion they were at least quite equal in sensitiveness.

-  Mr Ross  said that since the days of the daguerreotype he had soon nothing so extremely delicate and beautiful as the image on the gelatine film.

-  Mr Turnbull said he had tried the gelatine emulsion, both wet and dry, and although under somewhat disadvantag-eous circumstances, he had seen enough to convince him that it was much better than any other kind of emulsion

[BJP:  14 January 1876;  p.21]

Further Discussions

Edinburgh Photographic Society (EPS) discussed the gelatino-bromide process at their meeting on 1 March 1876.  AH Palmer's communication on the subject was read to the Society.  The reaction of the Edinburgh photographers to this communication was mixed:

-  Mr Lessels had tried gelatino-bromide plates without success

-  Mr Thomson did not expect it to replace the beer and albumen process which he considered to be slow, but compensated for by offering certainty and beauty.

-  Mr Neilson and Alexander Nicol and several other members also favoured the beer and albumen process. Mr Nicol commented that an exposure of two to three minutes was quite short enough for any ordinary purpose.

-  RH Bow suggested that the absence of the smell of ether was good reason, other things being equal, to strongly recommend the gelatine process.

-  Messrs Turnbull and Mathieson, after having worked successfully with the beer-and-albumen process for many years, tried the gelatino bromide process following AH Palmer's lecture.  However, they reported to an EPS Meeting on 4 October 1876, that they had abandoned the process due to difficulties with getting anything like a suitable density, and frilling and cracking up of the film;  so they recommend collodio-bromide process, but using ordinary draught bitter beer rather than tannin as a preservative.

[BJP:  10 Mar 1876;  p.117]

FP Moffat  -  Lecture to EPS -  1897

Three Papers were read during the Edinburgh Photographic Society's Meeting on 3 February 1897.  The three speakers spoke in favour of:

-  platinum paper

-  the carbon process

-  gelatino-chloride matt paper [a printing-out paper]

FP Moffat spoke in favour of the gelatino-chloride matt paper, claiming that it was not superior to the platinum or carbon processes, but it did have advantages over them.  He said:

" The matt chloride paper I use I purchase from the Paget Company who, I understand, make it specially for me.

F P Moffat stressed that he was speaking in favour of the matt paper.  He said he had found the gloss paper to be anything  but permanent, and beside, gloss is a thing he abominated.  He said he had been using the matt paper for four years and had not known any print to fade.

He described how he toned his prints, but said:

"I have not given you the formula for the toning and fixing baths, because if you buy the paper the formula will be sent along with it."

He summarised the advantages of the gelatino-chloride matt paper over platinotype as being:

"-  It very much resembles platinotype, but has a slightly warmer tone and finer surface.

-  It is easier to print, and not so liable to be affected by the weather.

-  It is quite permanent, and is only half the cost."