Cross Processing Photographic Film
Cross processing film is another way of achieving out of the ordinary results with photographic film. Cross processing is the process by which film is purposely processed in chemicals which are intended for a different type of film; positive film is processed in chemicals used for processing negative film and vice verse.
This is a common practice in the fashion photography and the music photography industry, where an increase in contrast is often desired. Positive film which is developed in negative film chemicals produce a negative image on a based lacking color, negative film processed in positive film chemicals produce a positive image that still retains the orange cast associated with film negatives.
Since positive film is less commonly used than negative film, the cross processing mostly occurs with positive on negative chemicals. Finalized images processed this way normally show unusual colors that have a high contrast.
Because the results of cross processing can be unpredictable, this adds to the mystery and fun of the technique. However many factors can make these color contrasts and color hues very unpredictable. Due to the introduction of the photo editing software programs that are now commonly available, this same effects can now be simulated with programs like Photoshop. The digital tools that are normally used are contrast,brightness, hue saturation, and curves.
Film can also be pushed and pulled during the processing stages. Pushing film is a technique in which the film which has been underexposed and is then overdeveloped by about 2 stops with the resulting images having a much higher contrast than if the film were developed in the standard fashion. Pulling the film is when the film is deliberately overexposed by about 2 stops and underdeveloped during processing with the resulting images showing a much lower contrast than if the film were developed as it was meant to be.
In both instances you must push or pull the film by about 2 stops when taking the photograph, the pulling and pushing developing process is done to compensate. The images done with this technique are mostly for special effects that can result in very pleasing images with pleasing tones, contrast and colors that are normally outside of the normal ranges and expectations most always are the results of these techniques.
Some typical cross processings are E6 film on C41 chemicals and the reverse, E6 or C41 film on black & white chemicals; the letters and numbers are those given by film manufacturers for the chemical formulas used to develop their films. Besides asking the photo lab to cross process your film, also inform them if you have pushed or pulled your film, the more they know the better they can do their job.
Another film processing technique used to create special effects, colors and contrast on the finalized images is push processing.
Here unlike the previous technique, the film is not pushed while filming. What is done is to develop the film for a longer period than what is recommended, and at warmer temperatures than normally used.
This produces the effect of increasing the sensitivity of the film, so a film with little sensitivity to light will have this sensitivity increased. This is very useful is you know that the images taken were underexposed and is used as a way of salvaging worthwhile images. Underexposing or overexposing film is not required.
The intention is of turning otherwise dull scenes into vibrant unusual ones. The results are an increase in contrast, increase in grain and a saturation in colors which are often distorted. This is sometimes done for its artistic value of the final product and very good examples find their way into art galleries, and photographic publications.
Some film manufactures produce film which has already been cross processed, pushed or pulled. Once the film has been exposed it is then developed under normal considerations by specific photo laboratories with the resulting prints maintaining the same effects as they would have been had a normal film been cross processed.
The main producer of cross processed film is currently the Lomography company under the brand name of Lomography 35mm X-pro Cross process film at a price of about $5.99 per roll.
- How to Cross Process C-41 color films and E-6 transparency films - I Still Shoot Film
How to Cross Process C-41 color films and E-6 transparency films I regularly get a lot of questions about cross processing, so I figured it might be helpful to do a little Cross Processing 101. First...