Using The Right Terms For Victorian Photography

Monday, April 23, 2012

This is easily the most random post I've ever written, but after messing around with the 'time machine' filters on Paint Shop Pro too much tonight I realized how much I hate when people just apply the terms 'daguerreotype' or 'tintype' to EVERY SINGLE PHOTO they see from the 19th century. There were a bunch of different photography techniques in use throughout the century, and many, if not most, of them overlapped. Let's talk about those now just so I can get this off my chest and fall asleep soundly.

To demonstrate the use of some of the more common ones, I took a drawing of Dustin, did some strange things with it in Paint Shop Pro, and then applied the time machine filters that were applicable to it.

Daguerreotypes were really only in use until the mid-1850s,
so Dustin as a daguerreotype really doesn't make much
sense because he's clearly an adult here and in the
mid-1850s he would have only been a young teenager.

Daguerreotypes
Daguerreotypes have the distinction of being the first photography technique to achieve any form of commercial success whatsoever. They became accessible to the masses in 1839 after years of development and research in France, but they were extremely fragile and susceptible to damage - if you're able to touch one, there's a good chance you'll be able to wipe the image off the plate.

I'm going to let Wikipedia explain the process here because I'm too tired to do any scientific writing:

The daguerreotype, along with the Tintype, is a photographic image allowing no direct transfer of the image onto another light-sensitive medium, as opposed to glass plate or paper negatives. Preparation of the silver-surfaced copper sheet prior to exposure resulted in the formation of a layer of photo-sensitive silver halide, and exposure to a scene or image through a lens formed a latent image. The latent image was made visible, or "developed", by subjecting the exposed plate to the fumes rising from a quantity of heated mercury. Daguerre was first to discover and publish (in the publication of the process and the English patent of 1839) the principle of latent image development.

The mercury vapour condensed on those places on the plate where the exposure light was most intense (highlights), and less so in darker areas of the image (shadows). This produced a picture in an amalgam, the mercury washing the silver out of the halides, solubilizing and amalgamating it into free silver particles which adhered to the exposed areas of the plate, leaving the unexposed silver halide ready to be removed by the fixing process. This resulted in the final unfixed image, which consisted of light and dark areas of grey amalgam on the plate. The developing box was constructed to allow inspection of the image through a yellow glass window to allow the photographer to determine when to stop development.

The next operation was to "fix" the photographic image permanently on the plate by dipping in a solution of hyposulphite of soda, often called "fixer" or "hypo", to dissolve the unexposed halides. Initially, Daguerre's process was to use a saturated salt solution for this step, but later adopted Herschel's suggestion of sodium thiosulphate, as did W. H. F. Talbot.

The image produced by this method is extremely fragile and susceptible to damage when handled. Practically all daguerreotypes are protected from accidental damage by a glass-fronted enclosure. It was discovered by experiment that treating the plate with heated gold chloride both tones and strengthens the image, although it remains quite delicate and requires a well-sealed enclosure to protect against touch as well as oxidation of the fine silver deposits forming the blacks in the image. The best-preserved daguerreotypes dating from the 19th century are sealed in robust glass cases evacuated of air and filled with a chemically inert gas, typically nitrogen.

That explained, let's point out that daguerreotypes were not the most dominant form of photography in the 19th century - many people erroneously think they are, and it drives me mad.  Daguerreotypes, as you can see in those four paragraphs there, took forever to make, and when a process is lengthy you can bet people, especially those industrious Victorians, will work their very hardest to shorten it up. Daguerreotypes were really only popular until the mid-1850s before faster, more efficient photographic techniques overtook them in popularity.

Let's talk about those now.

Ambrotypes and Tintypes

These two used very similar techniques and came into existence around the same time (1850s-60s), so I'm going to lump them together for the sake of simplifying this discussion for all of us. They both used the wet plate collodion process (for more on that, click here because it's complicated and I won't be bothered to explain something that someone else can explain better).

Ambrotypes and tintypes are actually placed on dark backgrounds as the images themselves are negatives, not positives. By placing them on a darker background, this gives them the appearance of a positive and produces the proper image. The only major difference that I can think of is that tintypes do not need to be mounted and protected the way ambrotypes do, which makes them more resilient and easier to take care of. Like daguerreotypes before them, ambrotypes were quite fragile and needed to be stored in cases, whilst tintypes could be taken out and displayed more simply.

By making an albumen print of Dustin playing the piano,
we've effectively turned him into a souvenir.

Albumen Prints

If you've seen a carte de visite, you've likely seen an albumen print. These were extremely easy to produce and were the first photography method to work well on paper instead of on plates, so they naturally exploded in popularity. All it did, in fact, was use the albumen in egg whites to hold photographic chemicals on paper, thus producing an image.

Albumen prints are the kind of photographs you'll see on calling cards, as mentioned above. They also make nice print souvenirs from tourist attractions and events, as well as postcard images. They have an attractive sepia-toned look to them and are extremely easy to mass produce due to their being printed on paper, so archivists like myself see a ton of them. They're frequently mounted on cardstock or the like when I come across them - it gives the paper a little more support and helps it stay in one piece longer, which is nice for us historian folks.

Now I'll have Wikipedia explain this process briefly to you:

1. A piece of paper, usually 100% cotton, is coated with an emulsion of egg white (albumen) and salt (sodium chloride or ammonium chloride), then dried. The albumen seals the paper and creates a slightly glossy surface for the sensitizer to rest on.
2. The paper is then dipped in a solution of silver nitrate and water which renders the surface sensitive to UV light.
3. The paper is then dried in the absence of UV light.
4. The dried, prepared paper is placed in a frame in direct contact under a negative. The negative is traditionally a glass negative with collodion emulsion, but this step can be performed with a modern silver halide negative, too. The paper with negative is then exposed to light until the image achieves the desired level of darkness, which is typically a little lighter than the end product. Though direct sunlight was used long ago, a UV exposure unit is preferable because it is more predictable, as the paper is most sensitive to ultraviolet light.
5. A bath of sodium thiosulfate fixes the print’s exposure, preventing further darkening.
6. Optional gold or selenium toning improves the photograph’s tone and stabilizes against fading. Depending on the toner, toning may be performed before or after fixing the print.

Because the image emerges as a direct result of exposure to light, without the aid of a developing solution, an albumen print may be said to be a printed rather than a developed photograph.

The table salt (sodium chloride) in the albumen emulsion forms silver chloride when in contact with silver nitrate. Silver chloride is unstable when exposed to light, which makes it decompose into silver and chlorine. The silver ion (Ag+) is reduced to silver (Ag) by addition of an electron during the development/printing process, and the remaining silver chloride is washed out during fixing. The black parts of the image are formed by metallic silver (Ag).

 See how much simpler that is than the earlier daguerreotype? Yeah. That's why this did so well.

Let's do one more before we go to bed, now, shall we?

Insert your Rhapsody In Blue puns here.

Cyanotype

This is actually how we used to make blueprints, people.

They weren't as popular as a photography technique, but cyanotypes developed during the 19th century and were an available filter on my copy of Paint Shop Pro, so I'm discussing them here briefly. The first person to use them for artistic photography was also a woman, Anna Atkins, who published a book of her cyanotypes in 1843, so I think that's pretty historically significant. Her book was published privately and in a couple of very limited editions, so it's an archivist's dream come true to find a copy (especially one like me who plans on focusing her graduate school education in Rare Books and Special Collections).

Here's how to make a cyanotype, via Wikipedia:

In a typical procedure, equal volumes of an 8.1% (w/v) solution of potassium ferricyanide and a 20% solution of ferric ammonium citrate are mixed. This mildly photosensitive solution is then applied to a receptive surface (such as paper or cloth) and allowed to dry in a dark place. Cyanotypes can be printed on any surface capable of soaking up the iron solution. Although watercolor paper is a preferred medium, cotton, wool and even gelatin sizing on nonporous surfaces have been used. Care should be taken to avoid alkaline-buffered papers which will cause degradation of the image over time.

A positive image can be produced by exposing it to a source of ultraviolet light (such as sunlight) with a negative. The UV light reduces the iron(III) to iron(II). This is followed by a complex reaction of the iron(II) complex with ferricyanide. The result is an insoluble, blue dye (ferric ferrocyanide) known as Prussian blue.

Upon exposure to ultraviolet light (such as that in sunlight), the iron in the unexposed areas will reduce, turning the paper a steel-grey-blue color. The extent of color change is dependent on the amount of UV light, but acceptable results are usually obtained after 10-20 minute exposures on a dark, gloomy day. The highlight values should appear overexposed as the water wash will reduce the final print values. Prints can be made with large format negatives and lithography film, or everyday objects can be used to make photograms.

After exposure, developing of the picture involves the yellow unreacted iron solution being rinsed off with running water. Although the blue color darkens upon drying, the effect can be accelerated by soaking the print in a 6% (v/v) solution of 3% (household) hydrogen peroxide. The water-soluble iron(III) salts are washed away, while the non-water-soluble Prussian blue remains in the paper. This is what gives the picture its typical blue color.

The overall contrast of the sensitizer solution can be increased with the addition of approximately 6 drops of 1% (w/v) solution potassium dichromate for every 2 ml of sensitizer solution.

Cyanotypes were not, as mentioned above, commonly used for photography except for artistic purposes. They were much more useful when producing blueprints, however, a practice that they were used for well until the 1900s, especially by engineers.

So there you have it, Victorian photography in a nutshell. Hopefully that'll clear some things up for everybody!