Agitation of solution to remove exhausted developer from film surface. 1
Density non-uniformity occurs on all camera negative film when developer turbulation is inadequate. Developer turbulation systems must be properly designed when the processors are built, to insure satisfactory tubulation for motion picture films.
When developer induced streaks are produced in processing machines, it is important to take immediate steps to determine the probable cause. For example, pressure increases as the holes become plugged; this reduces turbulation and produces non-uniformity.
1 Case, D., 1985, Motion Picture Film Processing, Media Manuals, Focal Press, London, Boston