3.5. Wet-plate collodion

Wet-plate collodion was the primary photographic process in use between the 1850s and 1880s. Collodion was a viscous liquid used to coat glass plates with light-sensitive salts, which needed to be wet when the picture was exposed. The glass negatives were contact-printed onto albumen-impregnated paper that was often toned with gold chloride, which imbued a purplishbrown color. The subject matter was very wideMatthew Brady, Alexander Gardner, and Timothy O'Sullivan depicted the American Civil War and the Gold Rush, while British photographers such as Roger Fenton and Francis Frith celebrated the Empire and its engineering achievements. As the technology improved, shorter exposure times and better optics enabled photographers to capture such scenes with unprecedented realism.

If you're starting with a color image, you can convert it to black and white to replicate the subdued quality and the pale, featureless skies typical of pictures made with the wet-plate collodion process. The toning needs to be simulated, and, given that the original photographs are now 150 years old, aging and distressing the image would also be appropriate.

This photograph was taken with a zoom lens and has a modern, close-cropped composition, but the subject matter is appropriate to the period. American Civil War enthsiasts, such as the subjects of this picture, go to great lengths to recreate the past, but often don't have good pictures of themselves in period dress. You may be presented with great photographic opportunities if you approach them directly and offer copies of your pictures.

Open your photograph and convert it to black and white by clicking the "Create new fill or adjustment layer" icon and selecting Channel Mixer. Check the Monochrome checkbox and adjust the sliders until you achieve the desired result. For wet-plate collodion effects, you should use more of the Blue channel and less of the Red; this will lighten blues and keep skin tones subdued. Next, add the tone. Click the "Create new fill or adjustment layer" icon and choose Curves. From the Channel drop-down menu, select the Red and Blue channels, and drag their curves slightly upward until you have a sepia-purple tone. This needs to be subtle, so be cautious with the effect. Open the image containing the texture you want to use to degrade the photograph. This may be something you have created in Photoshopbut what could be easier than using real materials? Here, I used my flatbed scanner to import a torn, folded manila envelopeperfect for distressing the photograph. In the texture image's Layers palette, pick up the image layer (by clicking and holding with the mouse) and drag it into the main photograph's window. Other modes, such as Hard Light and Pin Light, can also work, but they have strong effects and it's more important at this point to decide whether the texture is suitable. You can always try them later. If the texture looks right, use Edit > Transform or Ctrl/Cmd + T to resize and position it. Drag the handles at each side of the transformation box. When you're done, double-click inside the box or hit the Enter key. Check that the texture doesn't become too obvious once it is magnifiedyou may need to scan a larger piece of material, or re-scan at a higher resolution. The collodion mixture was hand-coated onto the glass plates and was often uneven. One way to simulate this is to select the picture layer, click the "Add layer mask" icon, apply the Clouds filter to the mask, and then immediately use Edit > Fade Clouds to moderate the resulting blotchiness. Other finishing touches include adding a rough border on a separate layer, and fine-tuning the toning. You can also increase the Canvas Size and stretch the texture layer to fitin this case, the folds of the paper show outside the image border, adding authenticity. The aging effects have produced a result that suspends disbelief enough for us to overlook the high quality of the lens and the close crop.