- A glass negative is covered with chemicals, known as collodion.
- The negative is dipped in silver nitrate to make it photosensitive.
- The wet plate is placed in a lightproof box.
- Inside its lightproof holder, the wet plate is inserted into the camera.
- A panel on the plate holder (called the dark slide) is removed, as is the lens cap, exposing the plate to light.
- The dark slide is replaced, thereby creating a lightproof box once more.
- The glass sheet - now a negative - is processed in the darkroom, turning the negative into a permanent image on the glass.
A Harvest of Death, by Timothy H. O'Sullivan. [Public domain], from the Library of Congress
I'll be the first to say that creating a great photograph is tough work.
But, boy, do we have it easy these days compared to the photographers of yesteryear...
I mean, I can get discouraged when shooting with my Nikon D810, but really, what do I have to complain about?
In fact, compared to the process that photographers had to use in the Civil War era, you and I have it easy.
By Miller (Photographic History of the Civil War) [Public domain], via Wikimedia Commons
To document the war, photographers used a wet plate collodion process.
Essentially, it involved chemically-coated panes of glass which were used as negatives.
As you might imagine, lugging these huge panes of glass around was both hard work and required great care to ensure they didn't break.
But believe it or not, the wet plate method was actually a simpler process to create a photographic negative than what came before it.
The Predecessor: The Calotype
By John Moffat [Public domain], via Wikimedia Commons
In 1841, William Henry Fox Talbot (pictured above) introduced the calotype method, which involved using silver chloride-coated paper to create images.
The silver chloride darkened when exposed to light to create the image, just like the digital sensors in our cameras today must be exposed to light to create an image.
Prior to Talbot's calotype, photographers often needed an hour or so to expose the paper to get a quality negative.
However, the calotype process slimmed that down to just a couple of minutes, mostly because the paper could be removed under the cover of darkness and chemically processed to further develop the image.
See page for author [Public domain], via Wikimedia Commons
The problem, of course, is that photographers needed to have a mobile darkroom with them in order to create prints.
The other issue is that this process produced images that weren't as clear or sharp (as seen above) as those created with the daguerreotype method.
So, on the one hand, the daguerreotype method produced sharp results but required exposures of an hour or more.
On the other hand, the calotype process required little time, but a laborious workflow to create images.
That's where the collodion process came in.
Making a Wet Plate Print
By Zp at cs.wikipedia [Public domain], from Wikimedia Commons
The great thing about the collodion process is that photographers could get sharp results and get an easily replicable negative, thus making the process of creating images much more streamlined.
Of course, "streamlined" should be taken with a grain of salt, as the process was still quite involved. The method's inventor, Frederick Scott Archer (pictured above), outlined the steps for creating a wet plate print in 1851:
Stone Wall Rear of Fredericksburg with Rebel Dead, by Andrew J. Russel. [Public domain], from the Library of Congress
From there, photographers often coated the glass plate with varnish to protect the image. After that, prints could be created using the same glass negative over and over again.
Clearly, it wasn't a process for the faint of heart, nor was the savage subject matter that Civil War photographers were tasked with documenting.
Pros and Cons of the Collodion Process
By William Micklethwaite [Public domain or Public domain], via Wikimedia Commons
As I noted earlier, the benefits of this type of photo-making are that the images were much clearer and sharper than a calotype while also being less laborious than a daguerreotype.
But that doesn't mean that it was a simple or easy process...
The collodion process required an on-site darkroom to prepare the negatives.
That meant that the vast majority of images taken with this process were taken in a studio.
The Civil War images seen throughout this article, however, had to be taken in the field. And that meant that photographers had to have a wagon full of gear (like the one seen above) just to create the glass negatives.
Additionally, though the collodion process allowed for much shorter exposure times, it still required a solid few seconds to expose the glass.
That meant that subjects had to be perfectly still for the duration, lest the image be a blurry mess.
If you've ever wondered why there's no photos of actual battle during the Civil War, that's why. As you can see in the image below, some of the men moving in the background are nothing but ghostly blurs.
Savage Station, VA Field Hospital After the Battle of June 27, by James F. Gibson. [Public domain], from the Library of Congress
That's to say nothing of the difficulty of traveling with all the required gear to create the images.
If you think we have it bad trying to travel today, consider having a wagon follow you around with the needed tools, chemicals, and all those glass negatives along for the rough ride.
It was such an involved process that only professional photographers were able to arrange all the needed materials, and they often had an assistant whose sole job was to mix the chemicals in the wagon while the photographer set up the heavy camera and tripod for the shot.
All in all, the time from the moment the wet plate was prepared until the time it was permanently exposed after process took about 10 minutes. That's a lot of work for a single image!
Nevertheless, the collodion method changed photography and allowed documentation of one of the worst conflicts in United States history.
And to be frank, the photographers documenting the Civil War certainly didn't have the most difficult job.
The hundreds of thousands of soldiers fighting on either side - often documented in haunting images like those seen above - certainly had much more on the line and much more to worry about than how quickly a photograph could be taken.