Considering that in the long run, the purpose of most of our densitometer measurements is to predict with some reasonable accuracy what the printing qualities will be of some arbitrary negative on some known printing paper, we should consider other approaches. One is to print the negative of the step wedge on the printing material in question and note the number of steps between black and white. A print of the original wedge directly on the printing material will show the effective number of steps in the SBR. Dividing that by the number of steps in the print of the negative will give the effective contrast index when those development conditions are used on any scene to be printed on that medium. Any kind of densitometer can probably be used to produce the H&D curve well enough to show peculiarities in the shape and give an idea about rendition of mid tones.