I suspect that Tony's experience of negatives varying from very thin to very thick is a consequence of slapdash temperature/time control. For a given film and developer, a consistent pair of temperature and time should give very consistent results. If the temperature can't be readily controlled, then at least create a table showing the correct time for a given temperature.(posted 9398 days ago)In addition, developers tend not to work very well at low temperatures. 20 deg C (68 F) is the usual minimum.