"Autochrome - Color Process Effect"

In 1907, the Lumière brothers introduced “autochrome,” the first commercially successful color process. Glass was coated in a fine mosaic of red, green, and blue dyed potato starches which acted as a filter over a light-sensitive emulsion.

During development, the emulsion layer became a black-and-white positive image, and the autochrome could then be projected or held up to the light, like an early version of a color slide or transparency. The process was enthusiastically received, and many photographers experimented with it, some of the best-known being Léon Gimpel in France and Frank Eugene and Alfred Stieglitz in the United States. Production of autochrome glass plates continued until the 1930s, when color film and printing first became available.

When you consider the characteristics of an autochrome, the most obvious is probably its Impressionistic or Pointillist appearance. Viewed close up, the colored particles can look rather like the color noise you sometimes find in digital photos. The particles also contribute to an overall softness, although this was sometimes the result of one-second exposure times and frosted-glass protective covers (you may want to simulate damage, too). In general, the colors are subdued and a little faded, in some cases unevenly.

Lumière manufactured autochrome plates for over 30 years and for many types of cameras, and no single subject matter predominated. Some French photographers used autochromes to record the events of World War I, but if you want a typical “turn of the century” subject, you won’t go far wrong with portraits or flower arrangements.

STEP 1
In the Layers palette, click the “Create new fill or new adjustment layer” icon and select Channel Mixer. Tick the Monochrome checkbox and adjust the channel sliders until you’re happy with the picture’s black-and-white tones. Unlike other early processes, you don’t need to bias the conversion in favor of the Blue channel—autochromists often countered daylight’s blue tone by using a yellow lens filter.

STEP 2
If you feel the image contrast needs adjustment, click the “Create new fill or adjustment layer” icon in the Layers palette, select Curves, and drag the curve. This S-shape increases contrast.

STEP 3
Duplicate the original picture layer. Use the Alt/Opt + Ctrl/Cmd + J keyboard combination, which triggers the New Layer dialog box. Name the new layer “Noise,” set its blending mode to Color, and click OK.

STEP 4
Blur the Noise layer slightly by selecting Filter > Blur > Gaussian Blur. Use a relatively low radius of around 7 pixels.

STEP 5
At this point it’s very helpful to work at 100%. Use View > Actual Pixels or Alt/Opt + Ctrl/Cmd + 0 (zero), then move the picture so you can see a key feature such as the apples. Now select Filter > Noise > Add Noise. This represents the random mosaic of colored particles, so ensure Monochrome is not ticked and choose the Gaussian method, as this produces a more random effect. Set a low amount so that the graininess is apparent at 100% but less obvious when you zoom out.

STEP 6
The Pointillize and Mosaic filters can be found via Filter > Pixelate. Again, set low values so the effect won’t be overwhelming. If the Mosaic filter looks too uniform, blur it or add some Noise..

STEP 7
Another optional step is to fade some of the colors. In the Layers palette, click the “Create new fill or adjustment layer” icon and select Hue/Saturation. Pick a color from the Edit drop-down box and reduce its Saturation. The reds and yellows were the accent color in the apples and the windows, so I faded the blues and cyans instead.

STEP 8
Experiment with the Noise layer’s blending mode. You could try Pin Light, but I found it too vivid fo r these flowers—as always, you need to trust your own judgment.