Editing Photographic processing (section)

=== Commercial processing ===
In commercial, central processing, the film is removed automatically or by an operator handling the film in a light proof bag from which it is fed into the processing machine. The processing machinery is generally run on a continuous basis with films spliced together in a continuous line. All the processing steps are carried out within a single processing machine with automatically controlled time, temperature and solution replenishment rate. The film or prints emerge washed and dry and ready to be cut by hand. Some modern machines also cut films and prints automatically, sometimes resulting in negatives cut across the middle of the frame where the space between frames is very thin or the frame edge is indistinct, as in an image taken in low light. Alternatively stores may use [[minilab]]s to develop films and make prints on the spot automatically without needing to send film to a remote, central facility for processing and printing.

Some processing chemistries used in minilabs require a minimum amount of processing per given amount of time to remain stable and usable. Once rendered unstable due to low use, the chemistry needs to be completely replaced, or replenishers can be added to restore the chemistry to a usable state. Some chemistries have been designed with this in mind given the declining demand for film processing in minilabs, often requiring specific handling. Often chemistries become damaged by oxidation. Also, development chemicals need to be thoroughly agitated constantly to ensure consistent results. The effectiveness (activity) of the chemistry is determined through pre-exposed film control strips.<ref>{{Cite web | url=https://imaging.kodakalaris.com/sites/uat/files/wysiwyg/retailers/chemistry/techpub/cis246.pdf | title=Operating Minilabs at Low Levels of Utilization Process C-41 and Process RA-4 | archive-url=https://web.archive.org/web/20200814103243/https://imaging.kodakalaris.com/sites/uat/files/wysiwyg/retailers/chemistry/techpub/cis246.pdf | archive-date=2020-08-14 }}</ref>