When you look at Alien: Resurrection’s cinematography, the first thing you’ll notice is it has a very different look from previous Alien films. It is more “gritty”.
The reason for this is nothing complicated. The secret is in simply skipping one step during the color negative processing in the laboratory. Basically it is a result of incomplete processing. Let’s take a look at how modern color negative film is processed.
Not every kind of color negatives are processed the same way. For example, films for still pictures are processed with a process called C-41. This process runs in all those film processors that you can see in photo labs where you develop your pictures.
The process used for developing motion picture color negative films is called ECN-2. It was first utilized in 1974 with the introduction of second generation Eastman color negative films, which was an earlier form of Eastman 5247 that was available in Europe for a short time before being introduced into the States in 1976 (as a matter of fact, the 5247 used in Alien was a modified version of this stock). ECN-2 was also used in the subsequent Kodak negative generations of film (Eastman EXR, vision, and the newest vision2).
Basically, this is how it works:
The film is run through a prebath. This prebath is used for softening rem-jet backing. Rem-jet is an antihalation layer on the back side (base side) of motion picture film. After the rem-jet layer has been softened, it is then removed.
Next, the film is passed through a developer. The developer creates an image out of exposed film layers.
Film stocks have three light-sensitive layers that have color couplers between them. Those couplers form the color image in the end. The developer reacts with the exposed silver halide layers in the film and the couplers in between the silver halide-sensitive layers.
The image is then formed in both the coupler layers and silver halide layers (where silver halide is converted to metallic silver). This way the silver halide layers serve as a mold for making color images in the couplers.
The results of this process depend greatly on the time the film spends in the developer. That’s why the development process needs to be stopped at just the right time. It is stopped with an acid stop bath. The film is then washed to remove the acid stop bath chemical and the developer. It is now clean and no longer light-sensitive.
Now comes the bleaching.
The bleach chemical converts the metallic silver back to silver halide so it can later be removed. The film is washed again to remove the bleach.
Fixing is the next stage. The fixer chemical converts the silver halide compounds into silver trisulfate complex salts. Part of this salt is removed during this stage and part by another wash.
The last step in film processing when the film is passed through the final rinse chemical that controls biological growth on the film. It is then dried and ready for printing, telecine, or vault storage.
Now, those are the basic steps to processing motion picture film. However, in the case of Alien: Resurrection, part of this process was altered.
The part that was skipped was the bleach and fixing process. This leaves the metallic silver, which would normally be converted and removed by those steps. The bleaching and fixing can be completely skipped or done only partially. In the case of Alien: Resurrection, they were partially done. This process has a lot of names like ENR, “skip-bleach”, “silver retention process”, etc.
And the result?
Generally, the color image is formed with those color couplers we discussed earlier. But with Alien: Resurrection, both color couplers and metallic silver form the image because the silver was not removed. As a result, the image was “reinforced” with the silver giving stronger blacks, stronger whites, more grain, higher contrast and less color.
Because the color negative process uses black and white (silver halide) layers to form the image on color couplers, if the silver is not removed, it is like combining color photography and black and white photography together. The color couplers provide the color, and the silver gives the image a “black and white film”-look.
This process is not a standard process, so film stock manufacturers do not take responsibility if something goes wrong. Filmmakers do it on their own risk. The process can be applied at any stage of film printing: to the original camera negative, the interpositive, the internegative or the release prints. And it can be done at different percentages. For example, you can leave 40% of silver if you like and bleach the rest. With Alien: Resurrection, 80% of the silver was retained.
In case something does go wrong, the process is reversable. The film can be processed again with bleach and fixer stages and the image will be back to normal.
So, why do filmmakers use it? Basically, it gives the expressive look of the black and white film stock. Black and white films do not look just like discolored color films. They have a unique look, and more contrast. Generally, it is done for the artistic reasons of the cinematographer and director, and is one often utilized by the film’s director, Jean-Pierre Jeunet.