I have worked with two different photographers recently and found varied views on the densitometer. The first said to test his film and camera he uses a subject with a five stop difference plus a piece of photo paper with 1/2 stop increments going up from total black to total white and gauges his EI and develpment from there. The other photographer does all that plus uses a densitometer to see if he is getting correct denity on his negs. both the results look the same too me and the first photographer has no use for densitometer. i know they measure density on the neg but couldn't a person already tell that with the above tests anyway. so I' m wondering what is the practical value of a densitometer to the pro photographer.