Hi there! I just finished developing a roll of HP5+ using these specs: - 3:2:150 dilution - 68 degrees Fahrenheit - 11 minutes, first minute of continuous agitation, followed by 10 second inversions every minute. Doing so, I received uneven negatives. Some of my negatives seem to have more contrast than others. Gary Arnold has scans of his Pyro negs; his example mirrors that of my HP5+ results: http://www.garyarnold.com/tags/photography What could be the cause of uneven development?