Hello, I'm new to your forum; I just discover it few weeks ago and find it very interesting for a newbie in Darkroom process. I have seen in a previous topic "Determining contrast grade in the Darkroom" that some people consider that the exposure time stay the same as you change contrast grade. I'm surprise by this affirmation and I would like to know if some of you have realize a calibration of their system like define by Paul Butzi in is web site. http://www.butzi.net/articles/vcce.htm Excuse me for my poor english. Best regards, Eric.