The interesting question came to my mind after I ran into this writing at the internet: http://www.imx.nl/photo/Film/Film/Film/page39.html According to writer, Erwin Puts, the developer does not have (any) practical effect to the film's characteristic curve. This site states exactly opposite: "Although I have not made detailed tests, it appears that HC-110 tends to produce an "upswept" characteristic curve with relatively high contrast in highlights (dark areas of the negative, light areas of the picture). With T-Max 100 film in particular, HC-110 produces an upswept curve, with more contrast in the highlights than in the shadows, while Xtol produces a more S-shaped curve (reminiscent of Tri-X Pan), with the most contrast in the midtones." I have always thought that developer have and different developers alters the shape of the characteristic curve. What is the thruth? Is there some more documented facts about this? Have to say that I have not never run sensitometric tests to same film with different developers... Perhaps I should do so.