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A cross processed shot of mannequins

Cross processing (sometimes abbreviated to Xpro) is the procedure of deliberately processing photographic film in a chemical solution intended for a different type of film. The effect was discovered independently by many different photographers often by mistake in the days of C-22 and E-4. The process is seen most often in fashion advertising and band photography, and in more recent years has become associated with the Lo-fi photography movement.^{[citation needed]}

Cross processing usually involves one of the two following methods:^{[citation needed]}

• Processing positive color reversal film in C-41 chemicals, resulting in a negative image on a colorless base
• Processing negative color print film in E-6 chemicals, resulting in a positive image but with the orange base of a normally processed color negative

History[link]

A digital cross process effect photo, notice the normally black areas now have a blue-ish hue.

The effect of cross processing has been well known since at least the early 1960s. Kodak published instructions and precautions for E-4 process in C-22 long ago. The National Geographic pictures of the astronaut Alan Shepard were taken on HS Ektachrome and pushed in C22. They were then masked and corrected for printing in Life magazine and National Geographic.^{[citation needed]}

Processes[link]

Traditionally, cross processing color slide film in C-41 process chemicals is most common. Some commercial-level photography/darkroom merchants will perform this developing process. However, cross processing can take place in many other forms, such as negative color print film and/or positive color reversal film in a black and white developer.

Other interesting effects can be obtained by bleaching color films processed in black and white chemistry using an hydrochloric acid dichromate mixture or using potassium triiodide (KI₃) solution. If these bleached films are then re-exposed to light and re-processed in their intended color chemistry, subtle, relatively low contrast, pastel effects are obtained^{[citation needed]}.

Color cross processed photographs are often characterized by unnatural colors and high contrast. The results of cross processing differ from case to case, as the results are determined by many factors such as the make and type of the film used, the amount of light exposed onto the film and the chemical used to develop the film.

Cross processing effects can be simulated in digital photography by a number of techniques involving the manipulation of contrast/brightness, hue/saturation and curves in image editors such as Adobe Photoshop or GIMP; specific settings and/or commands for "cross processing" are found in several such programs, including Photoshop and Picnik. However, these digital tools lack the unpredictable nature of regular cross processed images.

Examples of cross-processing[link]

• Tony Scott's 2005 film "Domino" was shot on color-reversal stock and cross-processed.^[1] Intentionally "blown out" and frequently shot at 6 frame/s, the film has a smeary, high-contrast look with a green-tendency.
• James Eaves and Johannes Roberts' 2004 film Hellbreeder was shot on color reversal stock and then cross processed.^[2]

See also[link]

• Redscale
• Photographic processes

References[link]

External links[link]

• Cross processing in Photoshop tutorial
• Cross processing in Gimp tutorial
• Cross processing in Gimp tutorial (German)
• Cross processing in Gimp tutorial (Spanish)
• Gimp script for cross processing