Abstract: The critical time in photographic processing apparatus is the time from when the first part of photographic material enters the apparatus to when the last part leaves the apparatus. During this time there are periods of time in which no processing takes place, for example, as the material is passed from one stage to the next. Described herein is a processing unit which minimizes the periods of time during which no processing is taking place. The unit comprises a processing tank (6) having processing solution (4) retained therein. Material (S) is fed into the tank (6) along a path (2), and around a looped path (8) until reaches a point (10) at which the material (S) can be deflected out of the tank (6), along path (14) and into a further processing tank (16), or can be deflected along path (12) so that further processing can take place in tank (6) prior to being passed on to the next stage.