C-41 process

C-41 is a standardized process in the chemical photography to the development of negative films. The name comes from the inventor of this method, Kodak; other companies such as Agfa, Fujifilm Tetenal or provide functionally equivalent to negative development processes under other names. For Agfa, the process was called, for example, as AP 70.

All current color negative films are today developed in the C- 41 process; other materials such as reversal films for slides own special methods such as e- sixth Some special black and white films like Kodak BW400CN or XP2 XP2 Super or Ilford can - in contrast to normal black and white films - are therefore processed in the quick development laboratory also in the C-41 process.

Processing

Developing color negative films is standardized, that is, different photosensitive films and the films from different manufacturers have the same development time. For films with higher light sensitivity, however, consume chemicals faster. From the sequence similar to the C-41 process of developing black and white films.

The original process is divided into the following steps:

The chemistry sets commercially available but are mostly built on a shortened process:

The developing ideally has a temperature of 38 ± 0.3 ° C, in the meantime, there are chemicals sentences with which color negatives by hand at 30 ° C, can be developed in the developing tank with larger temperature fluctuations. The bleach-fix ( blix ) has the same temperature as the developers, but the other steps are relatively insensitive to temperature and require a temperature of about 24 to 40 degrees Celsius.

Variants

There are still variations of the standard process, such as C -41, BNP (Agfa AP 71) and C-41 RA NP (Agfa AP 72 ) which are adapted to modern movies and allow a shorter processing time.