The manufacturer development times are just a starting point. Your thermometer, agitation, even water make a difference. I use Xtol and develop about 10-20% longer than Kodak's recomendation. Way back when I used D-76 and doggedly stuck to the recommended times, and overdeveloped alot of film. Did the same with Acufine and underdeveloped alot of film too. Developing your own B&W gives you unlimited control, so exercise it.(posted 9128 days ago)