All other chemical steps remain the same.Ĭolor negative films have greater exposure latitude than black-and-white films and can be pushed to reasonable lengths with good results. Push processing or up-rating film means underexposing the entire roll of film by one or more stops, then over-developing by 25-50% (per stop decrease). When the chemicals reach their processing capacity, throw them out and mix a new “kit”. Note the amount of film processed (in square inches) on a running tally, such as this C-41 processing log. While the developer must be discarded after processing, the bleach, fixer and stabilizer are returned to their respective jugs after each use. For example, a kit made up of three 1-gallon containers can process 1800 square inches of film. Together, they have the capacity to process a certain quantity of film. Instead of thinking of each chemical individually, these three are treated as a set.
The bleach, fixer and stabilizer make up what is referred to as the “kit’. We recommend mixing the developer in 5-gallon batches and the “kit” in one-gallon brown jugs. The bleach often ships ready-to-use and the others are easy to mix. Developer, bleach, fix and stabilizer are available at mail order photographic suppliers. The final step, stabilizer, protects the dyes from fading and promotes uniform drying. Fixing removes the silver, leaving a color image made of magenta, yellow and cyan layers. The second step in the C-41 process, bleaching, breaks down the silver image. This means that two different types of color negative film can be processed in the same tank. While the time and temperature of development for black and white film depends upon the brand and film speed, all C-41 film is processed at the same time and temperature, regardless of manufacturer or ISO. The developer makes the film’s latent image visible by changing exposed silver halides into metallic silver and activating color dyes in the film’s layers. The C-41 process involves particular chemicals at particular times and temperatures.įirst a water presoak softens the film to allow for more consistent developing. Kodak’s C-41 is the most common process for developing color negative films (Look for “Process C-41” on the film box or cartridge.). The more often you process film, the greater understanding you will have of how time and agitation can produce specific results. When processed correctly, negatives benefit from self-processing. The developer temperature must be 100˚F, with accepted variance of only ☑/4. Color has less latitude than black-and-white processing: processing times and temperatures must be spot on. 35mm-processing in the small tank utilizes the same method of loading the film on reels in a tank, pouring in chemicals and agitation, but with different chemicals, times and temperatures.
Color processing is similar to black-and-white processing. If you want to control the development process, you may want to process the film yourself. However, if you plan to shoot a large quantity of color film, self-processing can be less expensive.
Most commercial labs process color negative film with fast turnaround and at reasonable cost. Here, on our web resources, we describe the C-41 color negative development process. Refer to the book for information about film, descriptions of small tank processing, general work area, chemicals, safety and storage issues, and black and white film processing. You may, however, prefer to process your own film for 1) increased control over how your negatives look (For example, you can alter the development time to increase or decrease density and/or contrast), and 2) more options when photographing (For example, you can rate the film speed higher in your camera and compensate for this with processing). If you are photographing with film, you may find that having it processed at a lab saves time and gives desirable results. In order to view this image, the film must be developed, fixed and washed. In your camera, light exposes the film, creating a latent image.
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